diff --git a/manifest b/manifest index 6f7475645a..d0066e8ed9 100644 --- a/manifest +++ b/manifest @@ -1,5 +1,5 @@ -C Change\s'pragma\sforeign_key_list'\sto\sreturn\ssome\sextra\sinformation.\s(CVS\s5795) -D 2008-10-10T17:47:21 +C Add\sthe\sgenfkey\sprogram\sto\sthe\stool/\sdirectory.\s(CVS\s5796) +D 2008-10-10T17:58:27 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0 F Makefile.in 7fc26e087207e7a4a7723583dbd7997477af3b13 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654 @@ -622,6 +622,9 @@ F test/wherelimit.test 3464395714151cdce9f7f28a19d2cf344bd934c8 F test/zeroblob.test 792124852ec61458a2eb527b5091791215e0be95 F tool/diffdb.c 7524b1b5df217c20cd0431f6789851a4e0cb191b F tool/fragck.tcl 5265a95126abcf6ab357f7efa544787e5963f439 +F tool/genfkey.README d94b4423eef29e662898948f04a7dbe210c35e7a +F tool/genfkey.c 021979c7d2a58a230508b976095260a98c509cae +F tool/genfkey.test 182829596fb15785b94b2493c5f735b847d91076 F tool/lemon.c 6cb39632ef3bfec2cea8f81b4d7f63c09fe12802 F tool/lempar.c 770dc64b74429daf9611676f43bfbd7c1bed0152 F tool/memleak.awk 4e7690a51bf3ed757e611273d43fe3f65b510133 @@ -645,7 +648,7 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e -P ff50a8a7e5a15fac192939ff3206fa18d1c5a6dd -R d494f278258b84f1c8204facbe950e86 +P 3bb33cf59da49f13201c0226e964cda067a4e780 +R aef0f958c65788fc079e6ee823734d14 U danielk1977 -Z 706b49aeb2aa418df46d4fa5293d63e6 +Z 3eb8c7cc05cdf3fbc1c3afcf6ba604ca diff --git a/manifest.uuid b/manifest.uuid index 4914673fad..e5584ad8d4 100644 --- a/manifest.uuid +++ b/manifest.uuid @@ -1 +1 @@ -3bb33cf59da49f13201c0226e964cda067a4e780 \ No newline at end of file +84e73fe8a6f538c4b1bb4f641a661d6fafb60c76 \ No newline at end of file diff --git a/tool/genfkey.README b/tool/genfkey.README new file mode 100644 index 0000000000..7570f28635 --- /dev/null +++ b/tool/genfkey.README @@ -0,0 +1,138 @@ + +OVERVIEW + + The SQLite library is capable of parsing SQL foreign key constraints + supplied as part of CREATE TABLE statements, but it does not actually + implement them. However, most of the features of foreign keys may be + implemented using SQL triggers, which SQLite does support. This program + extracts foreign key definitions from an existing SQLite database and + outputs the set of CREATE TRIGGER statements required to implement + the foreign key constraints. + +CAPABILITIES + + An SQL foreign key is a constraint that requires that each row in + the "child" table corresponds to a row in the "parent" table. For + example, the following schema: + + CREATE TABLE parent(a, b, c, PRIMARY KEY(a, b)); + CREATE TABLE child(d, e, f, FOREIGN KEY(d, e) REFERENCES parent(a, b)); + + implies that for each row in table "child", there must be a row in + "parent" for which the expression (child.d==parent.a AND child.e==parent.b) + is true. The columns in the parent table are required to be either the + primary key columns or subject to a UNIQUE constraint. There is no such + requirement for the columns of the child table. + + At this time, all foreign keys are implemented as if they were + "MATCH NONE", even if the declaration specified "MATCH PARTIAL" or + "MATCH FULL". "MATCH NONE" means that if any of the key columns in + the child table are NULL, then there is no requirement for a corresponding + row in the parent table. So, taking this into account, the expression that + must be true for every row of the child table in the above example is + actually: + + (child.d IS NULL) OR + (child.e IS NULL) OR + (child.d==parent.a AND child.e==parent.b) + + Attempting to insert or update a row in the child table so that the + affected row violates this constraint results in an exception being + thrown. + + The effect of attempting to delete or update a row in the parent table + so that the constraint becomes untrue for one or more rows in the child + table depends on the "ON DELETE" or "ON UPDATE" actions specified as + part of the foreign key definition, respectively. Three different actions + are supported: "RESTRICT" (the default), "CASCADE" and "SET NULL". SQLite + will also parse the "SET DEFAULT" action, but this is not implemented + and "RESTRICT" is used instead. + + RESTRICT: Attempting to update or delete a row in the parent table so + that the constraint becomes untrue for one or more rows in + the child table is not allowed. An exception is thrown. + + CASCADE: Instead of throwing an exception, all corresponding child table + rows are either deleted (if the parent row is being deleted) + or updated to match the new parent key values (if the parent + row is being updated). + + SET NULL: Instead of throwing an exception, the foreign key fields of + all corresponding child table rows are set to NULL. + +LIMITATIONS + + Apart from those limitiations described above: + + * Implicit mapping to composite primary keys is not supported. If + a parent table has a composite primary key, then any child table + that refers to it must explicitly map each column. For example, given + the following definition of table "parent": + + CREATE TABLE parent(a, b, c, PRIMARY KEY(a, b)); + + only the first of the following two definitions of table "child" + is supported: + + CREATE TABLE child(d, e, f, FOREIGN KEY(d, e) REFERENCES parent(a, b)); + CREATE TABLE child(d, e, f, FOREIGN KEY(d, e) REFERENCES parent); + + An implicit reference to a composite primary key is detected as an + error when the program is run (see below). + + * SQLite does not support recursive triggers, and therefore this program + does not support recursive CASCADE or SET NULL foreign key + relationships. If the parent and the child tables of a CASCADE or + SET NULL foreign key are the same table, the generated triggers will + malfunction. This is also true if the recursive foreign key constraint + is indirect (for example if table A references table B which references + table A with a CASCADE or SET NULL foreign key constraint). + + Recursive CASCADE or SET NULL foreign key relationships are *not* + detected as errors when the program is run. Buyer beware. + +COMPILATION + + The source code for this program consists of a single C file - genfkey.c. + The only dependency is sqlite itself. Using gcc and the sqlite amalgamation + source code, it may be compiled using the following command: + + gcc genfkey.c sqlite3.c -o genfkey + + If compiled/linked against an SQLite version earlier than 3.6.4, then + all foreign key constraints are assumed to be "ON UPDATE RESTRICT" and + "ON DELETE RESTRICT". If linked against 3.6.4 or newer, "CASCADE" and + "SET NULL" are supported as well as "RESTRICT". All 3.x versions of SQLite + may use the created triggers definitions. + +USAGE + + genfkey ?--no-drop? ?--ignore-errors? + + When this program is run, it first checks the schema of the supplied SQLite + database for foreign key related errors or inconsistencies. For example, + a foreign key that refers to a parent table that does not exist, or + a foreign key that refers to columns in a parent table that are not + guaranteed to be unique. If such errors are found, a message for each + one is printed to stderr. + + If errors are found and the --ignore-errors option was not passed, the + program exits. Otherwise, a series of SQL trigger definitions (CREATE + TRIGGER statements) that implement the foreign key constraints found + in the database schema are written to stdout. If any errors were + found in the schema, no triggers for the problematic constraints are + output. The output CREATE TRIGGER statements should be run against the + database to enable enforcement of the foreign key constraints. For + example, for a database named "test.db" in the current working directory: + + $ genfkey ./test.db | sqlite3 ./test.db + + All triggers generated by this program have names that match the pattern + "genfkey*". Unless the --no-drop option is specified, then the program + also outputs a "DROP TRIGGER" statement for each trigger that exists + in the database with a name that matches this pattern. This allows the + program to be used to upgrade a database schema for which foreign key + triggers have already been installed (i.e. after new tables are created + or existing tables dropped). + + diff --git a/tool/genfkey.c b/tool/genfkey.c new file mode 100644 index 0000000000..952c5b8c02 --- /dev/null +++ b/tool/genfkey.c @@ -0,0 +1,870 @@ +/* +** 2008 October 10 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +************************************************************************* +** This file contains C code for 'genfkey', a program to generate trigger +** definitions that emulate foreign keys. See genfkey.README for details. +** +** $Id: genfkey.c,v 1.1 2008/10/10 17:58:27 danielk1977 Exp $ +*/ + +#include "sqlite3.h" +#include +#include +#include +#include + +/************************************************************************** +*************************************************************************** +** Start of virtual table implementations. +**************************************************************************/ + +/* The code in this file defines a sqlite3 virtual-table module that +** provides a read-only view of the current database schema. There is one +** row in the schema table for each column in the database schema. +*/ +#define SCHEMA \ +"CREATE TABLE x(" \ + "database," /* Name of database (i.e. main, temp etc.) */ \ + "tablename," /* Name of table */ \ + "cid," /* Column number (from left-to-right, 0 upward) */ \ + "name," /* Column name */ \ + "type," /* Specified type (i.e. VARCHAR(32)) */ \ + "not_null," /* Boolean. True if NOT NULL was specified */ \ + "dflt_value," /* Default value for this column */ \ + "pk" /* True if this column is part of the primary key */ \ +")" + +#define SCHEMA2 \ +"CREATE TABLE x(" \ + "database," /* Name of database (i.e. main, temp etc.) */ \ + "from_tbl," /* Name of table */ \ + "fkid," \ + "seq," \ + "to_tbl," \ + "from_col," \ + "to_col," \ + "on_update," \ + "on_delete," \ + "match" \ +")" + +#define SCHEMA3 \ +"CREATE TABLE x(" \ + "database," /* Name of database (i.e. main, temp etc.) */ \ + "tablename," /* Name of table */ \ + "seq," \ + "name," \ + "isunique" \ +")" + +#define SCHEMA4 \ +"CREATE TABLE x(" \ + "database," /* Name of database (i.e. main, temp etc.) */ \ + "indexname," /* Name of table */ \ + "seqno," \ + "cid," \ + "name" \ +")" + +typedef struct SchemaTable SchemaTable; +struct SchemaTable { + const char *zName; + const char *zObject; + const char *zPragma; + const char *zSchema; +} aSchemaTable[] = { + { "table_info", "table", "PRAGMA %Q.table_info(%Q)", SCHEMA }, + { "foreign_key_list", "table", "PRAGMA %Q.foreign_key_list(%Q)", SCHEMA2 }, + { "index_list", "table", "PRAGMA %Q.index_list(%Q)", SCHEMA3 }, + { "index_info", "index", "PRAGMA %Q.index_info(%Q)", SCHEMA4 }, + { 0, 0, 0, 0 } +}; + +typedef struct schema_vtab schema_vtab; +typedef struct schema_cursor schema_cursor; + +/* A schema table object */ +struct schema_vtab { + sqlite3_vtab base; + sqlite3 *db; + SchemaTable *pType; +}; + +/* A schema table cursor object */ +struct schema_cursor { + sqlite3_vtab_cursor base; + sqlite3_stmt *pDbList; + sqlite3_stmt *pTableList; + sqlite3_stmt *pColumnList; + int rowid; +}; + +/* +** Table destructor for the schema module. +*/ +static int schemaDestroy(sqlite3_vtab *pVtab){ + sqlite3_free(pVtab); + return 0; +} + +/* +** Table constructor for the schema module. +*/ +static int schemaCreate( + sqlite3 *db, + void *pAux, + int argc, const char *const*argv, + sqlite3_vtab **ppVtab, + char **pzErr +){ + int rc = SQLITE_NOMEM; + schema_vtab *pVtab; + SchemaTable *pType = &aSchemaTable[0]; + + if( argc>3 ){ + int i; + pType = 0; + for(i=0; aSchemaTable[i].zName; i++){ + if( 0==strcmp(argv[3], aSchemaTable[i].zName) ){ + pType = &aSchemaTable[i]; + } + } + if( !pType ){ + return SQLITE_ERROR; + } + } + + pVtab = sqlite3_malloc(sizeof(schema_vtab)); + if( pVtab ){ + memset(pVtab, 0, sizeof(schema_vtab)); + pVtab->db = db; + pVtab->pType = pType; + rc = sqlite3_declare_vtab(db, pType->zSchema); + } + *ppVtab = (sqlite3_vtab *)pVtab; + return rc; +} + +/* +** Open a new cursor on the schema table. +*/ +static int schemaOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){ + int rc = SQLITE_NOMEM; + schema_cursor *pCur; + pCur = sqlite3_malloc(sizeof(schema_cursor)); + if( pCur ){ + memset(pCur, 0, sizeof(schema_cursor)); + *ppCursor = (sqlite3_vtab_cursor *)pCur; + rc = SQLITE_OK; + } + return rc; +} + +/* +** Close a schema table cursor. +*/ +static int schemaClose(sqlite3_vtab_cursor *cur){ + schema_cursor *pCur = (schema_cursor *)cur; + sqlite3_finalize(pCur->pDbList); + sqlite3_finalize(pCur->pTableList); + sqlite3_finalize(pCur->pColumnList); + sqlite3_free(pCur); + return SQLITE_OK; +} + +/* +** Retrieve a column of data. +*/ +static int schemaColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){ + schema_cursor *pCur = (schema_cursor *)cur; + switch( i ){ + case 0: + sqlite3_result_value(ctx, sqlite3_column_value(pCur->pDbList, 1)); + break; + case 1: + sqlite3_result_value(ctx, sqlite3_column_value(pCur->pTableList, 0)); + break; + default: + sqlite3_result_value(ctx, sqlite3_column_value(pCur->pColumnList, i-2)); + break; + } + return SQLITE_OK; +} + +/* +** Retrieve the current rowid. +*/ +static int schemaRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){ + schema_cursor *pCur = (schema_cursor *)cur; + *pRowid = pCur->rowid; + return SQLITE_OK; +} + +static int finalize(sqlite3_stmt **ppStmt){ + int rc = sqlite3_finalize(*ppStmt); + *ppStmt = 0; + return rc; +} + +static int schemaEof(sqlite3_vtab_cursor *cur){ + schema_cursor *pCur = (schema_cursor *)cur; + return (pCur->pDbList ? 0 : 1); +} + +/* +** Advance the cursor to the next row. +*/ +static int schemaNext(sqlite3_vtab_cursor *cur){ + int rc = SQLITE_OK; + schema_cursor *pCur = (schema_cursor *)cur; + schema_vtab *pVtab = (schema_vtab *)(cur->pVtab); + char *zSql = 0; + + while( !pCur->pColumnList || SQLITE_ROW!=sqlite3_step(pCur->pColumnList) ){ + if( SQLITE_OK!=(rc = finalize(&pCur->pColumnList)) ) goto next_exit; + + while( !pCur->pTableList || SQLITE_ROW!=sqlite3_step(pCur->pTableList) ){ + if( SQLITE_OK!=(rc = finalize(&pCur->pTableList)) ) goto next_exit; + + assert(pCur->pDbList); + while( SQLITE_ROW!=sqlite3_step(pCur->pDbList) ){ + rc = finalize(&pCur->pDbList); + goto next_exit; + } + + /* Set zSql to the SQL to pull the list of tables from the + ** sqlite_master (or sqlite_temp_master) table of the database + ** identfied by the row pointed to by the SQL statement pCur->pDbList + ** (iterating through a "PRAGMA database_list;" statement). + */ + if( sqlite3_column_int(pCur->pDbList, 0)==1 ){ + zSql = sqlite3_mprintf( + "SELECT name FROM sqlite_temp_master WHERE type=%Q", + pVtab->pType->zObject + ); + }else{ + sqlite3_stmt *pDbList = pCur->pDbList; + zSql = sqlite3_mprintf( + "SELECT name FROM %Q.sqlite_master WHERE type=%Q", + sqlite3_column_text(pDbList, 1), pVtab->pType->zObject + ); + } + if( !zSql ){ + rc = SQLITE_NOMEM; + goto next_exit; + } + + rc = sqlite3_prepare(pVtab->db, zSql, -1, &pCur->pTableList, 0); + sqlite3_free(zSql); + if( rc!=SQLITE_OK ) goto next_exit; + } + + /* Set zSql to the SQL to the table_info pragma for the table currently + ** identified by the rows pointed to by statements pCur->pDbList and + ** pCur->pTableList. + */ + zSql = sqlite3_mprintf(pVtab->pType->zPragma, + sqlite3_column_text(pCur->pDbList, 1), + sqlite3_column_text(pCur->pTableList, 0) + ); + + if( !zSql ){ + rc = SQLITE_NOMEM; + goto next_exit; + } + rc = sqlite3_prepare(pVtab->db, zSql, -1, &pCur->pColumnList, 0); + sqlite3_free(zSql); + if( rc!=SQLITE_OK ) goto next_exit; + } + pCur->rowid++; + +next_exit: + /* TODO: Handle rc */ + return rc; +} + +/* +** Reset a schema table cursor. +*/ +static int schemaFilter( + sqlite3_vtab_cursor *pVtabCursor, + int idxNum, const char *idxStr, + int argc, sqlite3_value **argv +){ + int rc; + schema_vtab *pVtab = (schema_vtab *)(pVtabCursor->pVtab); + schema_cursor *pCur = (schema_cursor *)pVtabCursor; + pCur->rowid = 0; + finalize(&pCur->pTableList); + finalize(&pCur->pColumnList); + finalize(&pCur->pDbList); + rc = sqlite3_prepare(pVtab->db,"SELECT 0, 'main'", -1, &pCur->pDbList, 0); + return (rc==SQLITE_OK ? schemaNext(pVtabCursor) : rc); +} + +/* +** Analyse the WHERE condition. +*/ +static int schemaBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){ + return SQLITE_OK; +} + +/* +** A virtual table module that merely echos method calls into TCL +** variables. +*/ +static sqlite3_module schemaModule = { + 0, /* iVersion */ + schemaCreate, + schemaCreate, + schemaBestIndex, + schemaDestroy, + schemaDestroy, + schemaOpen, /* xOpen - open a cursor */ + schemaClose, /* xClose - close a cursor */ + schemaFilter, /* xFilter - configure scan constraints */ + schemaNext, /* xNext - advance a cursor */ + schemaEof, /* xEof */ + schemaColumn, /* xColumn - read data */ + schemaRowid, /* xRowid - read data */ + 0, /* xUpdate */ + 0, /* xBegin */ + 0, /* xSync */ + 0, /* xCommit */ + 0, /* xRollback */ + 0, /* xFindMethod */ + 0, /* xRename */ +}; + +/* +** Extension load function. +*/ +static int installSchemaModule(sqlite3 *db){ + sqlite3_create_module(db, "schema", &schemaModule, 0); + return 0; +} + +/************************************************************************** +*************************************************************************** +** End of virtual table implementations. +** Start of SQL user function implementations. +*/ + +/* +** sj(zValue, zJoin) +** +** The following block contains the implementation of an aggregate +** function that returns a string. Each time the function is stepped, +** it appends data to an internal buffer. When the aggregate is finalized, +** the contents of the buffer are returned. +** +** The first time the aggregate is stepped the buffer is set to a copy +** of the first argument. The second time and subsequent times it is +** stepped a copy of the second argument is appended to the buffer, then +** a copy of the first. +** +** Example: +** +** INSERT INTO t1(a) VALUES('1'); +** INSERT INTO t1(a) VALUES('2'); +** INSERT INTO t1(a) VALUES('3'); +** SELECT sj(a, ', ') FROM t1; +** +** => "1, 2, 3" +** +*/ +struct StrBuffer { + char *zBuf; +}; +typedef struct StrBuffer StrBuffer; +static void joinFinalize(sqlite3_context *context){ + StrBuffer *p; + p = (StrBuffer *)sqlite3_aggregate_context(context, sizeof(StrBuffer)); + sqlite3_result_text(context, p->zBuf, -1, SQLITE_TRANSIENT); + sqlite3_free(p->zBuf); +} +static void joinStep( + sqlite3_context *context, + int argc, + sqlite3_value **argv +){ + StrBuffer *p; + p = (StrBuffer *)sqlite3_aggregate_context(context, sizeof(StrBuffer)); + if( p->zBuf==0 ){ + p->zBuf = sqlite3_mprintf("%s", sqlite3_value_text(argv[0])); + }else{ + char *zTmp = p->zBuf; + p->zBuf = sqlite3_mprintf("%s%s%s", + zTmp, sqlite3_value_text(argv[1]), sqlite3_value_text(argv[0]) + ); + sqlite3_free(zTmp); + } +} + +/* +** dq(zString) +** +** This scalar function accepts a single argument and interprets it as +** a text value. The return value is the argument enclosed in double +** quotes. If any double quote characters are present in the argument, +** these are escaped. +** +** dq('the raven "Nevermore."') == '"the raven ""Nevermore."""' +*/ +static void doublequote( + sqlite3_context *context, + int argc, + sqlite3_value **argv +){ + int ii; + char *zOut; + char *zCsr; + const char *zIn = (const char *)sqlite3_value_text(argv[0]); + int nIn = sqlite3_value_bytes(argv[0]); + + zOut = sqlite3_malloc(nIn*2+3); + zCsr = zOut; + *zCsr++ = '"'; + for(ii=0; iinMalloc ){ + nMalloc += (nMalloc + 16); + zOut = (char *)sqlite3_realloc(zOut, nMalloc); + } + memcpy(&zOut[nOut], zCopy, nCopy); + i += nReplace; + nOut += nCopy; + } + + sqlite3_result_text(context, zOut, nOut, SQLITE_TRANSIENT); + sqlite3_free(zOut); +} + +/************************************************************************** +*************************************************************************** +** End of SQL user function implementations. +** Start of application implementation. +*/ + +typedef struct Options Options; +struct Options { + char *zDb; + int ignoreErrors; + int noDrop; +}; + +/* +** Print out a usage message for the command line and exit. This is +** called from processCmdLine() if the program is invoked incorrectly. +*/ +static int usage(char *zProgram){ + fprintf(stderr, + "Usage: %s ?--ignore-errors? ?--no-drop? \n", zProgram + ); + exit(-1); +} + +static void processCmdLine(int nArg, char **azArg, Options *p){ + int i; + assert( nArg>0 ); + if( nArg<2 ){ + usage(azArg[0]); + } + for(i=1; i<(nArg-1); i++){ + char *z = azArg[i]; + if( 0==strcmp(z, "--ignore-errors") ){ + p->ignoreErrors = 1; + } + else if( 0==strcmp(z, "--no-drop") ){ + p->noDrop = 1; + } + else usage(azArg[0]); + } + p->zDb = azArg[nArg-1]; +} + +/* +** A callback for sqlite3_exec() that prints its first argument to +** stdout followed by a newline. +*/ +static int printString(void *p, int nArg, char **azArg, char **azCol){ + printf("%s\n", azArg[0]); + return SQLITE_OK; +} + +int detectSchemaProblem( + sqlite3 *db, /* Database connection */ + const char *zMessage, /* English language error message */ + const char *zSql, /* SQL statement to run */ + int *pHasErrors /* Set *pHasErrors==1 if errors found */ +){ + sqlite3_stmt *pStmt; + int rc; + rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0); + if( rc!=SQLITE_OK ){ + return rc; + } + while( SQLITE_ROW==sqlite3_step(pStmt) ){ + char *zDel; + int iFk = sqlite3_column_int(pStmt, 0); + const char *zTab = (const char *)sqlite3_column_text(pStmt, 1); + fprintf(stderr, "Error in table %s: %s\n", zTab, zMessage); + zDel = sqlite3_mprintf( + "DELETE FROM temp.fkey WHERE from_tbl = %Q AND fkid = %d" + , zTab, iFk + ); + sqlite3_exec(db, zDel, 0, 0, 0); + sqlite3_free(zDel); + *pHasErrors = 1; + } + sqlite3_finalize(pStmt); + return SQLITE_OK; +} + +/* +** Create and populate temporary table "fkey". +*/ +static int populateTempTable(sqlite3 *db, char **pzErr, int *pHasErrors){ + int rc; + + rc = sqlite3_exec(db, + "CREATE VIRTUAL TABLE temp.v_fkey USING schema(foreign_key_list);" + "CREATE VIRTUAL TABLE temp.v_col USING schema(table_info);" + "CREATE VIRTUAL TABLE temp.v_idxlist USING schema(index_list);" + "CREATE VIRTUAL TABLE temp.v_idxinfo USING schema(index_info);" + + "CREATE TABLE temp.fkey AS " + "SELECT from_tbl, to_tbl, fkid, from_col, to_col, on_update, on_delete " + "FROM temp.v_fkey WHERE database = 'main';" + "CREATE TABLE temp.col AS " + "SELECT * FROM temp.v_col WHERE database = 'main';" + + , 0, 0, pzErr + ); + if( rc!=SQLITE_OK ) return rc; + + rc = detectSchemaProblem(db, "foreign key columns do not exist", + "SELECT fkid, from_tbl " + "FROM temp.fkey " + "WHERE to_col IS NOT NULL AND NOT EXISTS (SELECT 1 " + "FROM temp.col WHERE tablename=to_tbl AND name==to_col" + ")", pHasErrors + ); + if( rc!=SQLITE_OK ) return rc; + + /* At this point the temp.fkey table is mostly populated. If any foreign + ** keys were specified so that they implicitly refer to they primary + ** key of the parent table, the "to_col" values of the temp.fkey rows + ** are still set to NULL. + ** + ** This is easily fixed for single column primary keys, but not for + ** composites. With a composite primary key, there is no way to reliably + ** query sqlite for the order in which the columns that make up the + ** composite key were declared i.e. there is no way to tell if the + ** schema actually contains "PRIMARY KEY(a, b)" or "PRIMARY KEY(b, a)". + ** Therefore, this case is not handled. The following function call + ** detects instances of this case. + */ + rc = detectSchemaProblem(db, "implicit mapping to composite primary key", + "SELECT fkid, from_tbl " + "FROM temp.fkey " + "WHERE to_col IS NULL " + "GROUP BY fkid, from_tbl HAVING count(*) > 1", pHasErrors + ); + if( rc!=SQLITE_OK ) return rc; + + /* Detect attempts to implicitly map to the primary key of a table + ** that has no primary key column. + */ + rc = detectSchemaProblem(db, "implicit mapping to non-existant primary key", + "SELECT fkid, from_tbl " + "FROM temp.fkey " + "WHERE to_col IS NULL AND NOT EXISTS " + "(SELECT 1 FROM temp.col WHERE pk AND tablename = temp.fkey.to_tbl)" + , pHasErrors + ); + if( rc!=SQLITE_OK ) return rc; + + /* Fix all the implicit primary key mappings in the temp.fkey table. */ + rc = sqlite3_exec(db, + "UPDATE temp.fkey SET to_col = " + "(SELECT name FROM temp.col WHERE pk AND tablename=temp.fkey.to_tbl)" + " WHERE to_col IS NULL;" + , 0, 0, pzErr + ); + if( rc!=SQLITE_OK ) return rc; + + /* Now check that all all parent keys are either primary keys or + ** subject to a unique constraint. + */ + rc = sqlite3_exec(db, + "CREATE TABLE temp.idx2 AS SELECT " + "il.tablename AS tablename," + "ii.indexname AS indexname," + "ii.name AS col " + "FROM temp.v_idxlist AS il, temp.v_idxinfo AS ii " + "WHERE il.isunique AND il.database='main' AND ii.indexname = il.name;" + "INSERT INTO temp.idx2 SELECT tablename, 'pk', name FROM temp.col WHERE pk;" + + "CREATE TABLE temp.idx AS SELECT " + "tablename, indexname, sj(dq(col),',') AS cols " + "FROM (SELECT * FROM temp.idx2 ORDER BY col) " + "GROUP BY tablename, indexname;" + + "CREATE TABLE temp.fkey2 AS SELECT " + "fkid, from_tbl, to_tbl, sj(dq(to_col),',') AS cols " + "FROM (SELECT * FROM temp.fkey ORDER BY to_col) " + "GROUP BY fkid, from_tbl;" + , 0, 0, pzErr + ); + if( rc!=SQLITE_OK ) return rc; + rc = detectSchemaProblem(db, "foreign key is not unique", + "SELECT fkid, from_tbl " + "FROM temp.fkey2 " + "WHERE NOT EXISTS (SELECT 1 " + "FROM temp.idx WHERE tablename=to_tbl AND fkey2.cols==idx.cols" + ")", pHasErrors + ); + if( rc!=SQLITE_OK ) return rc; + + return rc; +} + +int main(int argc, char **argv){ + sqlite3 *db; + Options opt = {0, 0, 0}; + int rc; + int hasErrors = 0; + char *zErr = 0; + const int enc = SQLITE_UTF8; + + const char *zSql = + "SELECT multireplace('" + + "-- Triggers for foreign key mapping:\n" + "--\n" + "-- /from_readable/ REFERENCES /to_readable/\n" + "-- on delete /on_delete/\n" + "-- on update /on_update/\n" + "--\n" + + /* The "BEFORE INSERT ON " trigger. This trigger's job is to + ** throw an exception if the user tries to insert a row into the + ** referencing table for which there is no corresponding row in + ** the referenced table. + */ + "CREATE TRIGGER /name/_insert_referencing BEFORE INSERT ON /tbl/ WHEN \n" + " /key_notnull/ AND NOT EXISTS (SELECT 1 FROM /ref/ WHERE /cond1/)\n" + "BEGIN\n" + " SELECT RAISE(ABORT, ''constraint failed'');\n" + "END;\n" + + /* The "BEFORE UPDATE ON " trigger. This trigger's job + ** is to throw an exception if the user tries to update a row in the + ** referencing table causing it to correspond to no row in the + ** referenced table. + */ + "CREATE TRIGGER /name/_update_referencing BEFORE\n" + " UPDATE OF /rkey_list/ ON /tbl/ WHEN \n" + " /key_notnull/ AND \n" + " NOT EXISTS (SELECT 1 FROM /ref/ WHERE /cond1/)\n" + "BEGIN\n" + " SELECT RAISE(ABORT, ''constraint failed'');\n" + "END;\n" + + + /* The "BEFORE DELETE ON " trigger. This trigger's job + ** is to detect when a row is deleted from the referenced table to + ** which rows in the referencing table correspond. The action taken + ** depends on the value of the 'ON DELETE' clause. + */ + "CREATE TRIGGER /name/_delete_referenced BEFORE DELETE ON /ref/ WHEN\n" + " EXISTS (SELECT 1 FROM /tbl/ WHERE /cond2/)\n" + "BEGIN\n" + " /delete_action/\n" + "END;\n" + + /* The "BEFORE DELETE ON " trigger. This trigger's job + ** is to detect when the key columns of a row in the referenced table + ** to which one or more rows in the referencing table correspond are + ** updated. The action taken depends on the value of the 'ON UPDATE' + ** clause. + */ + "CREATE TRIGGER /name/_update_referenced AFTER\n" + " UPDATE OF /fkey_list/ ON /ref/ WHEN \n" + " EXISTS (SELECT 1 FROM /tbl/ WHERE /cond2/)\n" + "BEGIN\n" + " /update_action/\n" + "END;\n" + "'" + + /* These are used in the SQL comment written above each set of triggers */ + ", '/from_readable/', from_tbl || '(' || sj(from_col, ', ') || ')'" + ", '/to_readable/', to_tbl || '(' || sj(to_col, ', ') || ')'" + ", '/on_delete/', on_delete" + ", '/on_update/', on_update" + + ", '/name/', 'genfkey' || min(rowid)" + ", '/tbl/', dq(from_tbl)" + ", '/ref/', dq(to_tbl)" + ", '/key_notnull/', sj('new.' || dq(from_col) || ' IS NOT NULL', ' AND ')" + + ", '/fkey_list/', sj(to_col, ', ')" + ", '/rkey_list/', sj(from_col, ', ')" + + ", '/cond1/', sj(multireplace('new./from/ == /to/'" + ", '/from/', dq(from_col)" + ", '/to/', dq(to_col)" + "), ' AND ')" + ", '/cond2/', sj(multireplace('old./to/ == /from/'" + ", '/from/', dq(from_col)" + ", '/to/', dq(to_col)" + "), ' AND ')" + + ", '/update_action/', CASE on_update " + "WHEN 'SET NULL' THEN " + "multireplace('UPDATE /tbl/ SET /setlist/ WHERE /where/;' " + ", '/setlist/', sj(from_col||' = NULL',', ')" + ", '/tbl/', dq(from_tbl)" + ", '/where/', sj(from_col||' = old.'||dq(to_col),' AND ')" + ")" + "WHEN 'CASCADE' THEN " + "multireplace('UPDATE /tbl/ SET /setlist/ WHERE /where/;' " + ", '/setlist/', sj(dq(from_col)||' = new.'||dq(to_col),', ')" + ", '/tbl/', dq(from_tbl)" + ", '/where/', sj(dq(from_col)||' = old.'||dq(to_col),' AND ')" + ")" + "ELSE " + " 'SELECT RAISE(ABORT, ''constraint failed'');'" + "END " + + ", '/delete_action/', CASE on_delete " + "WHEN 'SET NULL' THEN " + "multireplace('UPDATE /tbl/ SET /setlist/ WHERE /where/;' " + ", '/setlist/', sj(from_col||' = NULL',', ')" + ", '/tbl/', dq(from_tbl)" + ", '/where/', sj(from_col||' = old.'||dq(to_col),' AND ')" + ")" + "WHEN 'CASCADE' THEN " + "multireplace('DELETE FROM /tbl/ WHERE /where/;' " + ", '/tbl/', dq(from_tbl)" + ", '/where/', sj(dq(from_col)||' = old.'||dq(to_col),' AND ')" + ")" + "ELSE " + " 'SELECT RAISE(ABORT, ''constraint failed'');'" + "END " + + ") FROM temp.fkey " + "GROUP BY from_tbl, fkid" + ; + + processCmdLine(argc, argv, &opt); + + /* Open the database handle. */ + rc = sqlite3_open_v2(opt.zDb, &db, SQLITE_OPEN_READONLY, 0); + if( rc!=SQLITE_OK ){ + fprintf(stderr, "Error opening database file: %s\n", sqlite3_errmsg(db)); + return -1; + } + + /* Create the special scalar and aggregate functions used by this program. */ + sqlite3_create_function(db, "dq", 1, enc, 0, doublequote, 0, 0); + sqlite3_create_function(db, "multireplace", -1, enc, db, multireplace, 0, 0); + sqlite3_create_function(db, "sj", 2, enc, 0, 0, joinStep, joinFinalize); + + /* Install the "schema" virtual table module */ + installSchemaModule(db); + + /* Create and populate a temp table with the information required to + ** build the foreign key triggers. See function populateTempTable() + ** for details. + */ + rc = populateTempTable(db, &zErr, &hasErrors); + if( rc!=SQLITE_OK ){ + fprintf(stderr, "Error reading database: %s\n", zErr); + return -1; + } + if( hasErrors && opt.ignoreErrors==0 ){ + return -1; + } + + printf("BEGIN;\n"); + + /* Unless the --no-drop option was specified, generate DROP TRIGGER + ** statements to drop any triggers in the database generated by a + ** previous run of this program. + */ + if( opt.noDrop==0 ){ + rc = sqlite3_exec(db, + "SELECT 'DROP TRIGGER' || ' ' || dq(name) || ';'" + "FROM sqlite_master " + "WHERE type='trigger' AND substr(name, 0, 7) == 'genfkey'" + , printString, 0, 0 + ); + if( rc!=SQLITE_OK ){ + const char *zMsg = sqlite3_errmsg(db); + fprintf(stderr, "Generating drop triggers failed: %s\n", zMsg); + return -1; + } + } + + /* Run the main query to create the trigger definitions. */ + rc = sqlite3_exec(db, zSql, printString, 0, 0); + if( rc!=SQLITE_OK ){ + fprintf(stderr, "Generating triggers failed: %s\n", sqlite3_errmsg(db)); + return -1; + } + + printf("COMMIT;\n"); + return 0; +} + diff --git a/tool/genfkey.test b/tool/genfkey.test new file mode 100644 index 0000000000..c55511f63f --- /dev/null +++ b/tool/genfkey.test @@ -0,0 +1,263 @@ + +package require sqlite3 + +proc do_test {name cmd expected} { + puts -nonewline "$name ..." + set res [uplevel $cmd] + if {$res eq $expected} { + puts Ok + } else { + puts Error + puts " Got: $res" + puts " Expected: $expected" + exit + } +} + +proc execsql {sql} { + uplevel [list db eval $sql] +} + +proc catchsql {sql} { + set rc [catch {uplevel [list db eval $sql]} msg] + list $rc $msg +} + +file delete -force test.db test.db.journal +sqlite3 db test.db + +# The following tests - genfkey-1.* - test RESTRICT foreign keys. +# +do_test genfkey-1.1 { + execsql { + CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c, UNIQUE(b, c)); + CREATE TABLE t2(e REFERENCES t1, f); + CREATE TABLE t3(g, h, i, FOREIGN KEY (h, i) REFERENCES t1(b, c)); + } +} {} +do_test genfkey-1.2 { + execsql [exec ./genfkey test.db] +} {} +do_test genfkey-1.3 { + catchsql { INSERT INTO t2 VALUES(1, 2) } +} {1 {constraint failed}} +do_test genfkey-1.4 { + execsql { + INSERT INTO t1 VALUES(1, 2, 3); + INSERT INTO t2 VALUES(1, 2); + } +} {} +do_test genfkey-1.5 { + execsql { INSERT INTO t2 VALUES(NULL, 3) } +} {} +do_test genfkey-1.6 { + catchsql { UPDATE t2 SET e = 5 WHERE e IS NULL } +} {1 {constraint failed}} +do_test genfkey-1.7 { + execsql { UPDATE t2 SET e = 1 WHERE e IS NULL } +} {} +do_test genfkey-1.8 { + execsql { UPDATE t2 SET e = NULL WHERE f = 3 } +} {} +do_test genfkey-1.9 { + catchsql { UPDATE t1 SET a = 10 } +} {1 {constraint failed}} +do_test genfkey-1.9a { + catchsql { UPDATE t1 SET a = NULL } +} {1 {datatype mismatch}} +do_test genfkey-1.10 { + catchsql { DELETE FROM t1 } +} {1 {constraint failed}} +do_test genfkey-1.11 { + execsql { UPDATE t2 SET e = NULL } +} {} +do_test genfkey-1.12 { + execsql { + UPDATE t1 SET a = 10 ; + DELETE FROM t1; + DELETE FROM t2; + } +} {} + +do_test genfkey-1.13 { + execsql { + INSERT INTO t3 VALUES(1, NULL, NULL); + INSERT INTO t3 VALUES(1, 2, NULL); + INSERT INTO t3 VALUES(1, NULL, 3); + } +} {} +do_test genfkey-1.14 { + catchsql { INSERT INTO t3 VALUES(3, 1, 4) } +} {1 {constraint failed}} +do_test genfkey-1.15 { + execsql { + INSERT INTO t1 VALUES(1, 1, 4); + INSERT INTO t3 VALUES(3, 1, 4); + } +} {} +do_test genfkey-1.16 { + catchsql { DELETE FROM t1 } +} {1 {constraint failed}} +do_test genfkey-1.17 { + catchsql { UPDATE t1 SET b = 10} +} {1 {constraint failed}} +do_test genfkey-1.18 { + execsql { UPDATE t1 SET a = 10} +} {} +do_test genfkey-1.19 { + catchsql { UPDATE t3 SET h = 'hello' WHERE i = 3} +} {1 {constraint failed}} + +do_test genfkey-1.X { + execsql { + DROP TABLE t1; + DROP TABLE t2; + DROP TABLE t3; + } +} {} + +# The following tests - genfkey-2.* - test CASCADE foreign keys. +# +do_test genfkey-2.1 { + execsql { + CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c, UNIQUE(b, c)); + CREATE TABLE t2(e REFERENCES t1 ON UPDATE CASCADE ON DELETE CASCADE, f); + CREATE TABLE t3(g, h, i, + FOREIGN KEY (h, i) + REFERENCES t1(b, c) ON UPDATE CASCADE ON DELETE CASCADE + ); + } +} {} +do_test genfkey-2.2 { + execsql [exec ./genfkey test.db] +} {} +do_test genfkey-2.3 { + execsql { + INSERT INTO t1 VALUES(1, 2, 3); + INSERT INTO t1 VALUES(4, 5, 6); + INSERT INTO t2 VALUES(1, 'one'); + INSERT INTO t2 VALUES(4, 'four'); + } +} {} +do_test genfkey-2.4 { + execsql { + UPDATE t1 SET a = 2 WHERE a = 1; + SELECT * FROM t2; + } +} {2 one 4 four} +do_test genfkey-2.5 { + execsql { + DELETE FROM t1 WHERE a = 4; + SELECT * FROM t2; + } +} {2 one} +do_test genfkey-2.6 { + execsql { + INSERT INTO t3 VALUES('hello', 2, 3); + UPDATE t1 SET c = 2; + SELECT * FROM t3; + } +} {hello 2 2} +do_test genfkey-2.7 { + execsql { + DELETE FROM t1; + SELECT * FROM t3; + } +} {} +do_test genfkey-2.X { + execsql { + DROP TABLE t1; + DROP TABLE t2; + DROP TABLE t3; + } +} {} + + +# The following tests - genfkey-3.* - test SET NULL foreign keys. +# +do_test genfkey-3.1 { + execsql { + CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c, UNIQUE(c, b)); + CREATE TABLE t2(e REFERENCES t1 ON UPDATE SET NULL ON DELETE SET NULL, f); + CREATE TABLE t3(g, h, i, + FOREIGN KEY (h, i) + REFERENCES t1(b, c) ON UPDATE SET NULL ON DELETE SET NULL + ); + } +} {} +do_test genfkey-3.2 { + execsql [exec ./genfkey test.db] +} {} +do_test genfkey-3.3 { + execsql { + INSERT INTO t1 VALUES(1, 2, 3); + INSERT INTO t1 VALUES(4, 5, 6); + INSERT INTO t2 VALUES(1, 'one'); + INSERT INTO t2 VALUES(4, 'four'); + } +} {} +do_test genfkey-3.4 { + execsql { + UPDATE t1 SET a = 2 WHERE a = 1; + SELECT * FROM t2; + } +} {{} one 4 four} +do_test genfkey-3.5 { + execsql { + DELETE FROM t1 WHERE a = 4; + SELECT * FROM t2; + } +} {{} one {} four} +do_test genfkey-3.6 { + execsql { + INSERT INTO t3 VALUES('hello', 2, 3); + UPDATE t1 SET c = 2; + SELECT * FROM t3; + } +} {hello {} {}} +do_test genfkey-2.7 { + execsql { + UPDATE t3 SET h = 2, i = 2; + DELETE FROM t1; + SELECT * FROM t3; + } +} {hello {} {}} +do_test genfkey-3.X { + execsql { + DROP TABLE t1; + DROP TABLE t2; + DROP TABLE t3; + } +} {} + +# The following tests - genfkey-4.* - test that errors in the schema +# are detected correctly. +# +do_test genfkey-4.1 { + execsql { + CREATE TABLE t1(a REFERENCES nosuchtable, b); + CREATE TABLE t2(a REFERENCES t1, b); + + CREATE TABLE t3(a, b, c, PRIMARY KEY(a, b)); + CREATE TABLE t4(a, b, c, FOREIGN KEY(c, b) REFERENCES t3); + + CREATE TABLE t5(a REFERENCES t4(d), b, c); + CREATE TABLE t6(a REFERENCES t4(a), b, c); + CREATE TABLE t7(a REFERENCES t3(a), b, c); + CREATE TABLE t8(a REFERENCES nosuchtable(a), b, c); + } +} {} + +do_test genfkey-4.X { + set rc [catch {exec ./genfkey test.db} msg] + list $rc $msg +} "1 {[string trim { +Error in table t5: foreign key columns do not exist +Error in table t8: foreign key columns do not exist +Error in table t4: implicit mapping to composite primary key +Error in table t1: implicit mapping to non-existant primary key +Error in table t2: implicit mapping to non-existant primary key +Error in table t6: foreign key is not unique +Error in table t7: foreign key is not unique +}]}" +