postgres/src/interfaces/jdbc/postgresql/PreparedStatement.java
1998-09-03 02:31:38 +00:00

596 lines
19 KiB
Java

package postgresql;
import java.io.*;
import java.math.*;
import java.sql.*;
import java.text.*;
import java.util.*;
import postgresql.largeobject.*;
import postgresql.util.*;
/**
* A SQL Statement is pre-compiled and stored in a PreparedStatement object.
* This object can then be used to efficiently execute this statement multiple
* times.
*
* <p><B>Note:</B> The setXXX methods for setting IN parameter values must
* specify types that are compatible with the defined SQL type of the input
* parameter. For instance, if the IN parameter has SQL type Integer, then
* setInt should be used.
*
* <p>If arbitrary parameter type conversions are required, then the setObject
* method should be used with a target SQL type.
*
* @see ResultSet
* @see java.sql.PreparedStatement
*/
public class PreparedStatement extends Statement implements java.sql.PreparedStatement
{
String sql;
String[] templateStrings;
String[] inStrings;
Connection connection;
/**
* Constructor for the PreparedStatement class.
* Split the SQL statement into segments - separated by the arguments.
* When we rebuild the thing with the arguments, we can substitute the
* args and join the whole thing together.
*
* @param conn the instanatiating connection
* @param sql the SQL statement with ? for IN markers
* @exception SQLException if something bad occurs
*/
public PreparedStatement(Connection connection, String sql) throws SQLException
{
super(connection);
Vector v = new Vector();
boolean inQuotes = false;
int lastParmEnd = 0, i;
this.sql = sql;
this.connection = connection;
for (i = 0; i < sql.length(); ++i)
{
int c = sql.charAt(i);
if (c == '\'')
inQuotes = !inQuotes;
if (c == '?' && !inQuotes)
{
v.addElement(sql.substring (lastParmEnd, i));
lastParmEnd = i + 1;
}
}
v.addElement(sql.substring (lastParmEnd, sql.length()));
templateStrings = new String[v.size()];
inStrings = new String[v.size() - 1];
clearParameters();
for (i = 0 ; i < templateStrings.length; ++i)
templateStrings[i] = (String)v.elementAt(i);
}
/**
* A Prepared SQL query is executed and its ResultSet is returned
*
* @return a ResultSet that contains the data produced by the
* query - never null
* @exception SQLException if a database access error occurs
*/
public java.sql.ResultSet executeQuery() throws SQLException
{
StringBuffer s = new StringBuffer();
int i;
for (i = 0 ; i < inStrings.length ; ++i)
{
if (inStrings[i] == null)
throw new SQLException("No value specified for parameter " + (i + 1));
s.append (templateStrings[i]);
s.append (inStrings[i]);
}
s.append(templateStrings[inStrings.length]);
return super.executeQuery(s.toString()); // in Statement class
}
/**
* Execute a SQL INSERT, UPDATE or DELETE statement. In addition,
* SQL statements that return nothing such as SQL DDL statements can
* be executed.
*
* @return either the row count for INSERT, UPDATE or DELETE; or
* 0 for SQL statements that return nothing.
* @exception SQLException if a database access error occurs
*/
public int executeUpdate() throws SQLException
{
StringBuffer s = new StringBuffer();
int i;
for (i = 0 ; i < inStrings.length ; ++i)
{
if (inStrings[i] == null)
throw new SQLException("No value specified for parameter " + (i + 1));
s.append (templateStrings[i]);
s.append (inStrings[i]);
}
s.append(templateStrings[inStrings.length]);
return super.executeUpdate(s.toString()); // in Statement class
}
/**
* Set a parameter to SQL NULL
*
* <p><B>Note:</B> You must specify the parameters SQL type (although
* PostgreSQL ignores it)
*
* @param parameterIndex the first parameter is 1, etc...
* @param sqlType the SQL type code defined in java.sql.Types
* @exception SQLException if a database access error occurs
*/
public void setNull(int parameterIndex, int sqlType) throws SQLException
{
set(parameterIndex, "null");
}
/**
* Set a parameter to a Java boolean value. The driver converts this
* to a SQL BIT value when it sends it to the database.
*
* @param parameterIndex the first parameter is 1...
* @param x the parameter value
* @exception SQLException if a database access error occurs
*/
public void setBoolean(int parameterIndex, boolean x) throws SQLException
{
set(parameterIndex, x ? "'t'" : "'f'");
}
/**
* Set a parameter to a Java byte value. The driver converts this to
* a SQL TINYINT value when it sends it to the database.
*
* @param parameterIndex the first parameter is 1...
* @param x the parameter value
* @exception SQLException if a database access error occurs
*/
public void setByte(int parameterIndex, byte x) throws SQLException
{
set(parameterIndex, (new Integer(x)).toString());
}
/**
* Set a parameter to a Java short value. The driver converts this
* to a SQL SMALLINT value when it sends it to the database.
*
* @param parameterIndex the first parameter is 1...
* @param x the parameter value
* @exception SQLException if a database access error occurs
*/
public void setShort(int parameterIndex, short x) throws SQLException
{
set(parameterIndex, (new Integer(x)).toString());
}
/**
* Set a parameter to a Java int value. The driver converts this to
* a SQL INTEGER value when it sends it to the database.
*
* @param parameterIndex the first parameter is 1...
* @param x the parameter value
* @exception SQLException if a database access error occurs
*/
public void setInt(int parameterIndex, int x) throws SQLException
{
set(parameterIndex, (new Integer(x)).toString());
}
/**
* Set a parameter to a Java long value. The driver converts this to
* a SQL BIGINT value when it sends it to the database.
*
* @param parameterIndex the first parameter is 1...
* @param x the parameter value
* @exception SQLException if a database access error occurs
*/
public void setLong(int parameterIndex, long x) throws SQLException
{
set(parameterIndex, (new Long(x)).toString());
}
/**
* Set a parameter to a Java float value. The driver converts this
* to a SQL FLOAT value when it sends it to the database.
*
* @param parameterIndex the first parameter is 1...
* @param x the parameter value
* @exception SQLException if a database access error occurs
*/
public void setFloat(int parameterIndex, float x) throws SQLException
{
set(parameterIndex, (new Float(x)).toString());
}
/**
* Set a parameter to a Java double value. The driver converts this
* to a SQL DOUBLE value when it sends it to the database
*
* @param parameterIndex the first parameter is 1...
* @param x the parameter value
* @exception SQLException if a database access error occurs
*/
public void setDouble(int parameterIndex, double x) throws SQLException
{
set(parameterIndex, (new Double(x)).toString());
}
/**
* Set a parameter to a java.lang.BigDecimal value. The driver
* converts this to a SQL NUMERIC value when it sends it to the
* database.
*
* @param parameterIndex the first parameter is 1...
* @param x the parameter value
* @exception SQLException if a database access error occurs
*/
public void setBigDecimal(int parameterIndex, BigDecimal x) throws SQLException
{
set(parameterIndex, x.toString());
}
/**
* Set a parameter to a Java String value. The driver converts this
* to a SQL VARCHAR or LONGVARCHAR value (depending on the arguments
* size relative to the driver's limits on VARCHARs) when it sends it
* to the database.
*
* @param parameterIndex the first parameter is 1...
* @param x the parameter value
* @exception SQLException if a database access error occurs
*/
public void setString(int parameterIndex, String x) throws SQLException
{
// if the passed string is null, then set this column to null
if(x==null)
set(parameterIndex,"null");
else {
StringBuffer b = new StringBuffer();
int i;
b.append('\'');
for (i = 0 ; i < x.length() ; ++i)
{
char c = x.charAt(i);
if (c == '\\' || c == '\'')
b.append((char)'\\');
b.append(c);
}
b.append('\'');
set(parameterIndex, b.toString());
}
}
/**
* Set a parameter to a Java array of bytes. The driver converts this
* to a SQL VARBINARY or LONGVARBINARY (depending on the argument's
* size relative to the driver's limits on VARBINARYs) when it sends
* it to the database.
*
* <p>Implementation note:
* <br>With postgresql, this creates a large object, and stores the
* objects oid in this column.
*
* @param parameterIndex the first parameter is 1...
* @param x the parameter value
* @exception SQLException if a database access error occurs
*/
public void setBytes(int parameterIndex, byte x[]) throws SQLException
{
LargeObjectManager lom = connection.getLargeObjectAPI();
int oid = lom.create();
LargeObject lob = lom.open(oid);
lob.write(x);
lob.close();
setInt(parameterIndex,oid);
}
/**
* Set a parameter to a java.sql.Date value. The driver converts this
* to a SQL DATE value when it sends it to the database.
*
* @param parameterIndex the first parameter is 1...
* @param x the parameter value
* @exception SQLException if a database access error occurs
*/
public void setDate(int parameterIndex, java.sql.Date x) throws SQLException
{
SimpleDateFormat df = new SimpleDateFormat("''"+connection.getDateStyle()+"''");
set(parameterIndex, df.format(x));
// The above is how the date should be handled.
//
// However, in JDK's prior to 1.1.6 (confirmed with the
// Linux jdk1.1.3 and the Win95 JRE1.1.5), SimpleDateFormat seems
// to format a date to the previous day. So the fix is to add a day
// before formatting.
//
// PS: 86400000 is one day
//
//set(parameterIndex, df.format(new java.util.Date(x.getTime()+86400000)));
}
/**
* Set a parameter to a java.sql.Time value. The driver converts
* this to a SQL TIME value when it sends it to the database.
*
* @param parameterIndex the first parameter is 1...));
* @param x the parameter value
* @exception SQLException if a database access error occurs
*/
public void setTime(int parameterIndex, Time x) throws SQLException
{
set(parameterIndex, "'" + x.toString() + "'");
}
/**
* Set a parameter to a java.sql.Timestamp value. The driver converts
* this to a SQL TIMESTAMP value when it sends it to the database.
*
* @param parameterIndex the first parameter is 1...
* @param x the parameter value
* @exception SQLException if a database access error occurs
*/
public void setTimestamp(int parameterIndex, Timestamp x) throws SQLException
{
set(parameterIndex, "'" + x.toString() + "'");
}
/**
* When a very large ASCII value is input to a LONGVARCHAR parameter,
* it may be more practical to send it via a java.io.InputStream.
* JDBC will read the data from the stream as needed, until it reaches
* end-of-file. The JDBC driver will do any necessary conversion from
* ASCII to the database char format.
*
* <P><B>Note:</B> This stream object can either be a standard Java
* stream object or your own subclass that implements the standard
* interface.
*
* @param parameterIndex the first parameter is 1...
* @param x the parameter value
* @param length the number of bytes in the stream
* @exception SQLException if a database access error occurs
*/
public void setAsciiStream(int parameterIndex, InputStream x, int length) throws SQLException
{
setBinaryStream(parameterIndex, x, length);
}
/**
* When a very large Unicode value is input to a LONGVARCHAR parameter,
* it may be more practical to send it via a java.io.InputStream.
* JDBC will read the data from the stream as needed, until it reaches
* end-of-file. The JDBC driver will do any necessary conversion from
* UNICODE to the database char format.
*
* <P><B>Note:</B> This stream object can either be a standard Java
* stream object or your own subclass that implements the standard
* interface.
*
* @param parameterIndex the first parameter is 1...
* @param x the parameter value
* @exception SQLException if a database access error occurs
*/
public void setUnicodeStream(int parameterIndex, InputStream x, int length) throws SQLException
{
setBinaryStream(parameterIndex, x, length);
}
/**
* When a very large binary value is input to a LONGVARBINARY parameter,
* it may be more practical to send it via a java.io.InputStream.
* JDBC will read the data from the stream as needed, until it reaches
* end-of-file.
*
* <P><B>Note:</B> This stream object can either be a standard Java
* stream object or your own subclass that implements the standard
* interface.
*
* @param parameterIndex the first parameter is 1...
* @param x the parameter value
* @exception SQLException if a database access error occurs
*/
public void setBinaryStream(int parameterIndex, InputStream x, int length) throws SQLException
{
throw new SQLException("InputStream as parameter not supported");
}
/**
* In general, parameter values remain in force for repeated used of a
* Statement. Setting a parameter value automatically clears its
* previous value. However, in coms cases, it is useful to immediately
* release the resources used by the current parameter values; this
* can be done by calling clearParameters
*
* @exception SQLException if a database access error occurs
*/
public void clearParameters() throws SQLException
{
int i;
for (i = 0 ; i < inStrings.length ; i++)
inStrings[i] = null;
}
/**
* Set the value of a parameter using an object; use the java.lang
* equivalent objects for integral values.
*
* <P>The given Java object will be converted to the targetSqlType before
* being sent to the database.
*
* <P>note that this method may be used to pass database-specific
* abstract data types. This is done by using a Driver-specific
* Java type and using a targetSqlType of java.sql.Types.OTHER
*
* @param parameterIndex the first parameter is 1...
* @param x the object containing the input parameter value
* @param targetSqlType The SQL type to be send to the database
* @param scale For java.sql.Types.DECIMAL or java.sql.Types.NUMERIC
* types this is the number of digits after the decimal. For
* all other types this value will be ignored.
* @exception SQLException if a database access error occurs
*/
public void setObject(int parameterIndex, Object x, int targetSqlType, int scale) throws SQLException
{
switch (targetSqlType)
{
case Types.TINYINT:
case Types.SMALLINT:
case Types.INTEGER:
case Types.BIGINT:
case Types.REAL:
case Types.FLOAT:
case Types.DOUBLE:
case Types.DECIMAL:
case Types.NUMERIC:
if (x instanceof Boolean)
set(parameterIndex, ((Boolean)x).booleanValue() ? "1" : "0");
else
set(parameterIndex, x.toString());
break;
case Types.CHAR:
case Types.VARCHAR:
case Types.LONGVARCHAR:
setString(parameterIndex, x.toString());
break;
case Types.DATE:
setDate(parameterIndex, (java.sql.Date)x);
break;
case Types.TIME:
setTime(parameterIndex, (Time)x);
break;
case Types.TIMESTAMP:
setTimestamp(parameterIndex, (Timestamp)x);
break;
case Types.OTHER:
setString(parameterIndex, ((PGobject)x).getValue());
break;
default:
throw new SQLException("Unknown Types value");
}
}
public void setObject(int parameterIndex, Object x, int targetSqlType) throws SQLException
{
setObject(parameterIndex, x, targetSqlType, 0);
}
/**
* This stores an Object into a parameter.
* <p>New for 6.4, if the object is not recognised, but it is
* Serializable, then the object is serialised using the
* postgresql.util.Serialize class.
*/
public void setObject(int parameterIndex, Object x) throws SQLException
{
if (x instanceof String)
setString(parameterIndex, (String)x);
else if (x instanceof BigDecimal)
setBigDecimal(parameterIndex, (BigDecimal)x);
else if (x instanceof Short)
setShort(parameterIndex, ((Short)x).shortValue());
else if (x instanceof Integer)
setInt(parameterIndex, ((Integer)x).intValue());
else if (x instanceof Long)
setLong(parameterIndex, ((Long)x).longValue());
else if (x instanceof Float)
setFloat(parameterIndex, ((Float)x).floatValue());
else if (x instanceof Double)
setDouble(parameterIndex, ((Double)x).doubleValue());
else if (x instanceof byte[])
setBytes(parameterIndex, (byte[])x);
else if (x instanceof java.sql.Date)
setDate(parameterIndex, (java.sql.Date)x);
else if (x instanceof Time)
setTime(parameterIndex, (Time)x);
else if (x instanceof Timestamp)
setTimestamp(parameterIndex, (Timestamp)x);
else if (x instanceof Boolean)
setBoolean(parameterIndex, ((Boolean)x).booleanValue());
else if (x instanceof PGobject)
setString(parameterIndex, ((PGobject)x).getValue());
else
setLong(parameterIndex, connection.putObject(x));
}
/**
* Some prepared statements return multiple results; the execute method
* handles these complex statements as well as the simpler form of
* statements handled by executeQuery and executeUpdate
*
* @return true if the next result is a ResultSet; false if it is an
* update count or there are no more results
* @exception SQLException if a database access error occurs
*/
public boolean execute() throws SQLException
{
StringBuffer s = new StringBuffer();
int i;
for (i = 0 ; i < inStrings.length ; ++i)
{
if (inStrings[i] == null)
throw new SQLException("No value specified for parameter " + (i + 1));
s.append (templateStrings[i]);
s.append (inStrings[i]);
}
s.append(templateStrings[inStrings.length]);
return super.execute(s.toString()); // in Statement class
}
/**
* Returns the SQL statement with the current template values
* substituted.
*/
public String toString() {
StringBuffer s = new StringBuffer();
int i;
for (i = 0 ; i < inStrings.length ; ++i)
{
if (inStrings[i] == null)
s.append( '?' );
else
s.append (templateStrings[i]);
s.append (inStrings[i]);
}
s.append(templateStrings[inStrings.length]);
return s.toString();
}
// **************************************************************
// END OF PUBLIC INTERFACE
// **************************************************************
/**
* There are a lot of setXXX classes which all basically do
* the same thing. We need a method which actually does the
* set for us.
*
* @param paramIndex the index into the inString
* @param s a string to be stored
* @exception SQLException if something goes wrong
*/
private void set(int paramIndex, String s) throws SQLException
{
if (paramIndex < 1 || paramIndex > inStrings.length)
throw new SQLException("Parameter index out of range");
inStrings[paramIndex - 1] = s;
}
}