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SQL/JSON: Fix casting for integer EXISTS columns in JSON_TABLE

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The current method of coercing the boolean result value of
JsonPathExists() to the target type specified for an EXISTS column,
which is to call the type's input function via json_populate_type(),
leads to an error when the target type is integer, because the
integer input function doesn't recognize boolean literal values as
valid.

Instead use the boolean-to-integer cast function for coercion in that
case so that using integer or domains thereof as type for EXISTS
columns works. Note that coercion for ON ERROR values TRUE and FALSE
already works like that because the parser creates a cast expression
including the cast function, but the coercion of the actual result
value is not handled by the parser.

Tests by Jian He.

Reported-by: Jian He <jian.universality@gmail.com>
Author: Jian He <jian.universality@gmail.com>
Author: Amit Langote <amitlangote09@gmail.com>
Discussion: https://postgr.es/m/CACJufxEo4sUjKCYtda0_qt9tazqqKPmF1cqhW9KBOUeJFqQd2g@mail.gmail.com
Backpatch-through: 17
This commit is contained in:
Amit Langote 2024-07-30 10:12:23 +09:00
parent 74c96699be
commit 7f56eaff2f
5 changed files with 102 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
src/backend/executor/execExpr.c
View File

@ -93,6 +93,7 @@ static void ExecInitJsonExpr(JsonExpr *jsexpr, ExprState *state,
ExprEvalStep *scratch);
static void ExecInitJsonCoercion(ExprState *state, JsonReturning *returning,
ErrorSaveContext *escontext, bool omit_quotes,
bool exists_coerce,
Datum *resv, bool *resnull);
@ -4329,7 +4330,9 @@ ExecInitJsonExpr(JsonExpr *jsexpr, ExprState *state,
jsestate->jump_eval_coercion = state->steps_len;
ExecInitJsonCoercion(state, jsexpr->returning, escontext,
jsexpr->omit_quotes, resv, resnull);
jsexpr->omit_quotes,
jsexpr->op == JSON_EXISTS_OP,
resv, resnull);
}
else if (jsexpr->use_io_coercion)
{
@ -4410,7 +4413,8 @@ ExecInitJsonExpr(JsonExpr *jsexpr, ExprState *state,
/* Step to coerce the ON ERROR expression if needed */
if (jsexpr->on_error->coerce)
ExecInitJsonCoercion(state, jsexpr->returning, escontext,
jsexpr->omit_quotes, resv, resnull);
jsexpr->omit_quotes, false,
resv, resnull);
/*
* Add a COERCION_FINISH step to check for errors that may occur when
@ -4466,7 +4470,8 @@ ExecInitJsonExpr(JsonExpr *jsexpr, ExprState *state,
/* Step to coerce the ON EMPTY expression if needed */
if (jsexpr->on_empty->coerce)
ExecInitJsonCoercion(state, jsexpr->returning, escontext,
jsexpr->omit_quotes, resv, resnull);
jsexpr->omit_quotes, false,
resv, resnull);
/*
* Add a COERCION_FINISH step to check for errors that may occur when
@ -4502,6 +4507,7 @@ ExecInitJsonExpr(JsonExpr *jsexpr, ExprState *state,
static void
ExecInitJsonCoercion(ExprState *state, JsonReturning *returning,
ErrorSaveContext *escontext, bool omit_quotes,
bool exists_coerce,
Datum *resv, bool *resnull)
{
ExprEvalStep scratch = {0};
@ -4512,8 +4518,13 @@ ExecInitJsonCoercion(ExprState *state, JsonReturning *returning,
scratch.resnull = resnull;
scratch.d.jsonexpr_coercion.targettype = returning->typid;
scratch.d.jsonexpr_coercion.targettypmod = returning->typmod;
scratch.d.jsonexpr_coercion.json_populate_type_cache = NULL;
scratch.d.jsonexpr_coercion.json_coercion_cache = NULL;
scratch.d.jsonexpr_coercion.escontext = escontext;
scratch.d.jsonexpr_coercion.omit_quotes = omit_quotes;
scratch.d.jsonexpr_coercion.exists_coerce = exists_coerce;
scratch.d.jsonexpr_coercion.exists_cast_to_int = exists_coerce &&
getBaseType(returning->typid) == INT4OID;
scratch.d.jsonexpr_coercion.exists_check_domain = exists_coerce &&
DomainHasConstraints(returning->typid);
ExprEvalPushStep(state, &scratch);
}

46
src/backend/executor/execExprInterp.c
View File

@ -4303,13 +4303,7 @@ ExecEvalJsonExprPath(ExprState *state, ExprEvalStep *op,
if (!error)
{
*op->resnull = false;
if (jsexpr->use_json_coercion)
*op->resvalue = DirectFunctionCall1(jsonb_in,
BoolGetDatum(exists) ?
CStringGetDatum("true") :
CStringGetDatum("false"));
else
*op->resvalue = BoolGetDatum(exists);
*op->resvalue = BoolGetDatum(exists);
}
}
break;
@ -4550,10 +4544,46 @@ ExecEvalJsonCoercion(ExprState *state, ExprEvalStep *op,
{
ErrorSaveContext *escontext = op->d.jsonexpr_coercion.escontext;
/*
* Prepare to call json_populate_type() to coerce the boolean result of
* JSON_EXISTS_OP to the target type. If the the target type is integer
* or a domain over integer, call the boolean-to-integer cast function
* instead, because the integer's input function (which is what
* json_populate_type() calls to coerce to scalar target types) doesn't
* accept boolean literals as valid input. We only have a special case
* for integer and domains thereof as it seems common to use those types
* for EXISTS columns in JSON_TABLE().
*/
if (op->d.jsonexpr_coercion.exists_coerce)
{
if (op->d.jsonexpr_coercion.exists_cast_to_int)
{
/* Check domain constraints if any. */
if (op->d.jsonexpr_coercion.exists_check_domain &&
!domain_check_safe(*op->resvalue, *op->resnull,
op->d.jsonexpr_coercion.targettype,
&op->d.jsonexpr_coercion.json_coercion_cache,
econtext->ecxt_per_query_memory,
(Node *) escontext))
{
*op->resnull = true;
*op->resvalue = (Datum) 0;
}
else
*op->resvalue = DirectFunctionCall1(bool_int4, *op->resvalue);
return;
}
*op->resvalue = DirectFunctionCall1(jsonb_in,
DatumGetBool(*op->resvalue) ?
CStringGetDatum("true") :
CStringGetDatum("false"));
}
*op->resvalue = json_populate_type(*op->resvalue, JSONBOID,
op->d.jsonexpr_coercion.targettype,
op->d.jsonexpr_coercion.targettypmod,
&op->d.jsonexpr_coercion.json_populate_type_cache,
&op->d.jsonexpr_coercion.json_coercion_cache,
econtext->ecxt_per_query_memory,
op->resnull,
op->d.jsonexpr_coercion.omit_quotes,

6
src/include/executor/execExpr.h
View File

@ -708,7 +708,11 @@ typedef struct ExprEvalStep
Oid targettype;
int32 targettypmod;
bool omit_quotes;
void *json_populate_type_cache;
/* exists_* fields only relevant for JSON_EXISTS_OP. */
bool exists_coerce;
bool exists_cast_to_int;
bool exists_check_domain;
void *json_coercion_cache;
ErrorSaveContext *escontext;
} jsonexpr_coercion;
} d;

34
src/test/regress/expected/sqljson_jsontable.out
View File

@ -175,7 +175,7 @@ FROM json_table_test vals
[1, 1.23, "2", "aaaaaaa", "foo", null, false, true, {"aaa": 123}, "[1,2]", "\"str\""] | 6 | f | 0 | | false
[1, 1.23, "2", "aaaaaaa", "foo", null, false, true, {"aaa": 123}, "[1,2]", "\"str\""] | 7 | f | 0 | | false
[1, 1.23, "2", "aaaaaaa", "foo", null, false, true, {"aaa": 123}, "[1,2]", "\"str\""] | 8 | f | 0 | | false
[1, 1.23, "2", "aaaaaaa", "foo", null, false, true, {"aaa": 123}, "[1,2]", "\"str\""] | 9 | t | 0 | | true
[1, 1.23, "2", "aaaaaaa", "foo", null, false, true, {"aaa": 123}, "[1,2]", "\"str\""] | 9 | t | 1 | 1 | true
[1, 1.23, "2", "aaaaaaa", "foo", null, false, true, {"aaa": 123}, "[1,2]", "\"str\""] | 10 | f | 0 | | false
[1, 1.23, "2", "aaaaaaa", "foo", null, false, true, {"aaa": 123}, "[1,2]", "\"str\""] | 11 | f | 0 | | false
(14 rows)
@ -549,12 +549,18 @@ SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a int PATH 'lax $.a' DEFAULT
(1 row)
-- JSON_TABLE: EXISTS PATH types
SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a int4 EXISTS PATH '$.a'));
SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a int4 EXISTS PATH '$.a' ERROR ON ERROR)); -- ok; can cast to int4
a
---
0
(1 row)
SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a int4 EXISTS PATH '$' ERROR ON ERROR)); -- ok; can cast to int4
a
---
1
(1 row)
SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a int2 EXISTS PATH '$.a'));
ERROR: could not coerce ON ERROR expression (FALSE) to the RETURNING type
DETAIL: invalid input syntax for type smallint: "false"
@ -588,6 +594,30 @@ SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a jsonb EXISTS PATH '$.a'));
false
(1 row)
-- EXISTS PATH domain over int
CREATE DOMAIN dint4 AS int;
CREATE DOMAIN dint4_0 AS int CHECK (VALUE <> 0 );
SELECT a, a::bool FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a dint4 EXISTS PATH '$.a' ));
a | a
---+---
0 | f
(1 row)
SELECT a, a::bool FROM JSON_TABLE(jsonb '{"a":1}', '$' COLUMNS (a dint4_0 EXISTS PATH '$.b'));
ERROR: could not coerce ON ERROR expression (FALSE) to the RETURNING type
DETAIL: value for domain dint4_0 violates check constraint "dint4_0_check"
SELECT a, a::bool FROM JSON_TABLE(jsonb '{"a":1}', '$' COLUMNS (a dint4_0 EXISTS PATH '$.b' ERROR ON ERROR));
ERROR: value for domain dint4_0 violates check constraint "dint4_0_check"
SELECT a, a::bool FROM JSON_TABLE(jsonb '{"a":1}', '$' COLUMNS (a dint4_0 EXISTS PATH '$.b' FALSE ON ERROR));
ERROR: could not coerce ON ERROR expression (FALSE) to the RETURNING type
DETAIL: value for domain dint4_0 violates check constraint "dint4_0_check"
SELECT a, a::bool FROM JSON_TABLE(jsonb '{"a":1}', '$' COLUMNS (a dint4_0 EXISTS PATH '$.b' TRUE ON ERROR));
a | a
---+---
1 | t
(1 row)
DROP DOMAIN dint4, dint4_0;
-- JSON_TABLE: WRAPPER/QUOTES clauses on scalar columns
SELECT * FROM JSON_TABLE(jsonb '"world"', '$' COLUMNS (item text PATH '$' KEEP QUOTES ON SCALAR STRING));
item

13
src/test/regress/sql/sqljson_jsontable.sql
View File

@ -262,7 +262,8 @@ SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a int PATH 'strict $.a' DEFAU
SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a int PATH 'lax $.a' DEFAULT 1 ON EMPTY DEFAULT 2 ON ERROR)) jt;
-- JSON_TABLE: EXISTS PATH types
SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a int4 EXISTS PATH '$.a'));
SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a int4 EXISTS PATH '$.a' ERROR ON ERROR)); -- ok; can cast to int4
SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a int4 EXISTS PATH '$' ERROR ON ERROR)); -- ok; can cast to int4
SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a int2 EXISTS PATH '$.a'));
SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a int8 EXISTS PATH '$.a'));
SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a float4 EXISTS PATH '$.a'));
@ -273,6 +274,16 @@ SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a char(5) EXISTS PATH '$.a' E
SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a json EXISTS PATH '$.a'));
SELECT * FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a jsonb EXISTS PATH '$.a'));
-- EXISTS PATH domain over int
CREATE DOMAIN dint4 AS int;
CREATE DOMAIN dint4_0 AS int CHECK (VALUE <> 0 );
SELECT a, a::bool FROM JSON_TABLE(jsonb '"a"', '$' COLUMNS (a dint4 EXISTS PATH '$.a' ));
SELECT a, a::bool FROM JSON_TABLE(jsonb '{"a":1}', '$' COLUMNS (a dint4_0 EXISTS PATH '$.b'));
SELECT a, a::bool FROM JSON_TABLE(jsonb '{"a":1}', '$' COLUMNS (a dint4_0 EXISTS PATH '$.b' ERROR ON ERROR));
SELECT a, a::bool FROM JSON_TABLE(jsonb '{"a":1}', '$' COLUMNS (a dint4_0 EXISTS PATH '$.b' FALSE ON ERROR));
SELECT a, a::bool FROM JSON_TABLE(jsonb '{"a":1}', '$' COLUMNS (a dint4_0 EXISTS PATH '$.b' TRUE ON ERROR));
DROP DOMAIN dint4, dint4_0;
-- JSON_TABLE: WRAPPER/QUOTES clauses on scalar columns
SELECT * FROM JSON_TABLE(jsonb '"world"', '$' COLUMNS (item text PATH '$' KEEP QUOTES ON SCALAR STRING));
SELECT * FROM JSON_TABLE(jsonb '"world"', '$' COLUMNS (item text PATH '$' OMIT QUOTES ON SCALAR STRING));