A prepared SQL command can be parsed and contain input and output parameters. Parameters are marked with a '?' or ':<name>' tag. All DML commands can be parsed. DDL commands can be parsed, too. However, it is not recommended to do so. Prepared SQL commands increase the performance since they are parsed only once and executed several times. Applications only need to change the content of the bound parameters and execute the command again.
All prepared SQL commands are stored in an internally managed ParseInfo Cache . The ParseInfo Cache shares this information with different prepared SQL statements within the same connection.
The SQL statement may contain ASCII or UCS2 characters and must not zero-terminated. The execute() member function converts it to the adequate code set considering the code of the database. Therefore it is possible to write portable code for UNICODE and non-UNICODE databases.
SQLDBC_PreparedStatement *stmt = conn->createPreparedStatement(); SQLDBC_Retcode rc = stmt->prepare("SELECT * FROM DUAL"); if (rc != SQLDBC_OK) { Handle error ... } rc = stmt->execute(); if (rc != SQLDBC_OK) { Handle error ... }
Definition at line 2132 of file SQLDBC.h.
enum SQLDBC::SQLDBC_Statement::ResultSetType [inherited] |
enum SQLDBC::SQLDBC_Statement::ConcurrencyType [inherited] |
enum SQLDBC::SQLDBC_Statement::HoldabilityType [inherited] |
SQLDBC_Retcode SQLDBC::SQLDBC_PreparedStatement::prepare | ( | const char * | sql, | |
const SQLDBC_Length | sqlLength, | |||
const SQLDBC_StringEncoding | encoding | |||
) |
Parses an ASCII/UNICODE coded SQL statement.
sql | SQL statement to be prepared. | |
sqlLength | Length in bytes of the SQL statement. | |
encoding | Character code of the SQL statement.
|
SQLDBC_Retcode SQLDBC::SQLDBC_PreparedStatement::prepare | ( | const char * | sql, | |
const SQLDBC_StringEncoding | encoding | |||
) |
Parses an ASCII/UNICODE coded zero-terminated SQL statement.
sql | The zero-terminated string containing the SQL statement to be prepared. The code of the given string depends from the encoding argument. | |
encoding | The character encoding of the sql argument.
|
SQLDBC_Retcode SQLDBC::SQLDBC_PreparedStatement::prepare | ( | const char * | sql | ) |
Parses a zero-terminated ASCII coded SQL statement.
sql | The zero-terminated string containing the SQL statement to be prepared. The given string must be ASCII coded.
|
SQLDBC_Retcode SQLDBC::SQLDBC_PreparedStatement::execute | ( | ) |
Executes a prepared SQL statement.
The SQL statement must be prepared beforehand, and the appropriate binding variables must have been set with the bindParameter() member function.
SQLDBC_ParameterMetaData* SQLDBC::SQLDBC_PreparedStatement::getParameterMetaData | ( | ) |
Retrieves an SQLDBC_ParameterMetaData object that contains information about the parameters used.
SQLDBC_ResultSetMetaData* SQLDBC::SQLDBC_PreparedStatement::getResultSetMetaData | ( | ) |
Retrieves an SQLDBC_ResultSetMetaData object that contains information about the columns of the SQLDBC_ResultSet object.
The SQLDBC_ResultSetMetaData contains information about the columns of the SQLDBC_ResultSet object that will be returned when the SQLDBC_PreparedStatement object is executed. Because an SQLDBC_PreparedStatement object is parsed, it is possible to get information about the ResultSet object that will be returned without having to execute the SQL statement. Consequently, it is possible to use this method with an SQLDBC_PreparedStatement object rather than executing it and then calling the getResultSetMetaData() method on the returned SQLDBC_ResultSet object.
SQLDBC_Retcode SQLDBC::SQLDBC_PreparedStatement::setBatchSize | ( | SQLDBC_UInt4 | rowarraysize | ) |
Sets the size of the row array for a batch execute.
rowarraysize | [in] Number of rows for batch execution. |
SQLDBC_UInt4 SQLDBC::SQLDBC_PreparedStatement::getPreferredBatchSize | ( | ) |
Get the optimum size for batch execution. Applications that can adjust the size of records delivered at batch execution
4294967295U
if the application should deliver as many rows as it can itself handle. SQLDBC_Retcode SQLDBC::SQLDBC_PreparedStatement::clearParameters | ( | ) |
Clears the information about parameters. All information about parameters that have been bound before using either the bindParameter
or the bindParameterAddr
method is cleared.
SQLDBC_Retcode SQLDBC::SQLDBC_PreparedStatement::bindParameter | ( | const SQLDBC_UInt2 | Index, | |
const SQLDBC_HostType | Type, | |||
void * | paramAddr, | |||
SQLDBC_Length * | LengthIndicator, | |||
const SQLDBC_Length | Size, | |||
const SQLDBC_Bool | Terminate = SQLDBC_TRUE | |||
) |
Binds a user supplied memory buffer to an input and/or output parameter of an SQL statement.
A parameter is a '?' or ':<name>' placeholder in an SQL statement. Applications should use SQLDBC_ParameterMetadata to retrieve information about the type and length of the parameters in an SQL statement.
Index | [in] Index of the parameter, starting with 1 | |
Type | [in] Host type of the parameter | |
paramAddr | [in] A pointer to a buffer for the parameter's data | |
LengthIndicator | [in|out] Pointer to parameter length or indicator.
| |
Size | [in] Byte length of the parameter | |
Terminate | [in] Specifies that the output buffer must be finished with a C-style zero-terminator. The Terminate flag works only for the non-integral character hostvar types (SQLDBC_HOSTTYPE_ASCII, SQLDBC_HOSTTYPE_UCS2 or SQLDBC_HOSTTYPE_UTF8). |
SQLDBC_Retcode SQLDBC::SQLDBC_PreparedStatement::bindParameterAddr | ( | const SQLDBC_UInt2 | Index, | |
const SQLDBC_HostType | Type, | |||
void * | paramAddr, | |||
SQLDBC_Length * | LengthIndicator, | |||
const SQLDBC_Length | Size, | |||
const SQLDBC_Bool | Terminate = SQLDBC_TRUE | |||
) |
Binds an input and/or output parameter by address.
Binding by adress is useful when the application uses buffers that are allocated as an array of pointers (C function calloc)
A parameter is a '?' or ':<name>' placeholder in an SQL statement. Applications should use SQLDBC_ParameterMetadata to retrieve information about the type and length of the parameters in a SQL statement.
Index | [in] Index of the parameter, starting with 1. | |
Type | [in] Host type of the parameter | |
paramAddr | [in] Pointer to a pointer for the parameter's data. | |
LengthIndicator | [in|out] Pointer to parameter length or indicator.
| |
Size | [in] Byte length of the parameter | |
Terminate | [in] Specifies that the output buffer must be finished with a C-style zero-terminator. The Terminate flag works only for the non-integral character hostvar types (SQLDBC_HOSTTYPE_ASCII, SQLDBC_HOSTTYPE_UCS2 or SQLDBC_HOSTTYPE_UTF8). |
SQLDBC_Retcode SQLDBC::SQLDBC_PreparedStatement::setBindingType | ( | SQLDBC_size_t | size | ) |
Sets the binding type for parameters.
The value of the parameter offset is normally 0, which implies a column-wise binding. If it is set to a value other than 0, a row-wise binding is applied. So, the address offset of the respective next parameter value is computed differently for column-wise and row-wise binding:
size | The parameter offset for row-wise binding, if set to 0, column-wise binding is applied. |
SQLDBC_Retcode SQLDBC::SQLDBC_PreparedStatement::nextParameter | ( | SQLDBC_Int2 & | paramIndex, | |
void *& | paramAddr | |||
) |
Switches to the next input parameter if the application uses data at execute parameters.
After calling this member function, the paramIndex and the paramAddr parameters are set.
nextParameterByIndex
instead.paramIndex | Index of the next parameter. | |
paramAddr | The data pointer that was supplied when binding the parameter, plus any offset that originates from a batch execution sequence (including row-wise binding). |
SQLDBC_Retcode SQLDBC::SQLDBC_PreparedStatement::nextParameterByIndex | ( | SQLDBC_Int2 & | paramIndex, | |
void *& | paramAddr | |||
) |
Switches to the input parameter if the application uses data at execute parameters, After calling this member function, the paramIndex and the paramAddr parameters are set. The paramIndex parameter is used to select the next parameter that is processed. You cannot process parameters that are bound to LONG columns before all parameters that are bound to non-LONG columns have been processed for a row.
paramIndex | Index of the next parameter that shall be processed, or 0 if the application has no preferred next parameter. | |
paramAddr | The data pointer that was supplied when binding the parameter, plus any offset that originates from a batch execution sequence (including row-wise binding). |
SQLDBC_Retcode SQLDBC::SQLDBC_PreparedStatement::putData | ( | void * | paramAddr, | |
SQLDBC_Length * | paramLengthIndicator | |||
) |
Put data for an input parameter.
paramAddr | Pointer to the data which is to be assigned to the SQL parameter. The type of the data must match the type assigned by the bindParameter() member function. | |
paramLengthIndicator | [in] Pointer to parameter length or indicator. |
SQLDBC_Retcode SQLDBC::SQLDBC_PreparedStatement::getObject | ( | const SQLDBC_Int4 | Index, | |
const SQLDBC_HostType | Type, | |||
void * | paramAddr, | |||
SQLDBC_Length * | LengthIndicator, | |||
const SQLDBC_Length | Size, | |||
const SQLDBC_Bool | Terminate = SQLDBC_TRUE | |||
) |
Retrieves and converts the value of the specified output column of the current row to a buffer.
The specified column value in the current row of this SQLDBC_PreparedStatement object is converted to the given length and SQLDBC_HostType and written to the output parameter buffer pointed to paramAddr.
It can be called multiple times to retrieve character or binary data in parts. For fixed-length datatypes getObject retrieves the same data multiple times. Mixing variable-length datatypes and fixed-length datatypes may produce unexpected results.
Index | Index of the column. The first column is column number 1, the second is column number 2, ... | |
Type | Parameter type of the output buffer. | |
paramAddr | A pointer to the parameters output buffer. | |
LengthIndicator | [out] Pointer to a variable that stores the column length or the indicator value SQLDBC_NULL_DATA if the column contains the NULL value. For character data it contains on success the number of bytes copied to the buffer, except the number of bytes necessary for the zero-terminator, if the Terminate flag was set. If the source string exceeds the Size value SQLDBC_DATA_TRUNC will be returned and LengthIndicator is set to the number of bytes (except the terminator bytes) needed to copy without truncation. | |
Size | [in] Length of the parameter buffer in bytes. The Size argument is only necessary for non-integral data types. For character data the Size argument must be large enough to store the terminator byte(s) if the Terminate flag is set. | |
Terminate | [in] Specifies that the output buffer must be finished with a C-style zero-terminator. The Terminate flag works only for the host var type character (ASCII, UCS2 or UTF8). As a default, all character data is zero-terminated. |
SQLDBC_Retcode SQLDBC::SQLDBC_PreparedStatement::getObject | ( | const SQLDBC_Int4 | Index, | |
const SQLDBC_HostType | Type, | |||
void * | paramAddr, | |||
SQLDBC_Length * | LengthIndicator, | |||
const SQLDBC_Length | Size, | |||
SQLDBC_Length | StartPos, | |||
const SQLDBC_Bool | Terminate = SQLDBC_TRUE | |||
) |
Retrieves and converts the value with an start offset in of the specified output column from a of the current row to a buffer.
The specified column value in the current row of this SQLDBC_PreparedStatement object is converted to the given length and SQLDBC_HostType and written to the output parameter buffer pointed to paramAddr.
It can be called multiple times to retrieve character or binary data in parts. For fixed-length datatypes getObject retrieves the same data multiple times. Mixing variable-length datatypes and fixed-length datatypes may produce unexpected results.
Index | Index of the column. The first column is column number 1, the second is column number 2, ... | |
Type | Parameter type of the output buffer. | |
paramAddr | A pointer to the parameters output buffer. | |
LengthIndicator | [out] Pointer to a variable that stores the column length or the indicator value SQLDBC_NULL_DATA if the column contains the NULL value. For character data it contains on success the number of bytes copied to the buffer, except the number of bytes necessary for the zero-terminator, if the Terminate flag was set. If the source string exceeds the Size value SQLDBC_DATA_TRUNC will be returned and LengthIndicator is set to the number of bytes (except the terminator bytes) needed to copy without truncation. | |
Size | [in] Length of the parameter buffer in bytes. The Size argument is only necessary for non-integral data types. For character data the Size argument must be large enough to store the terminator byte(s) if the Terminate flag is set. | |
StartPos | [in] Start position in long column from which on the data should be retrieved. Start position is counted in bytes from 1. Negative StartPos counts from the end of the long column. | |
Terminate | [in] Specifies that the output buffer must be finished with a C-style zero-terminator. The Terminate flag works only for the host var type character (ASCII, UCS2 or UTF8). As a default, all character data is zero-terminated. |
SQLDBC_Retcode SQLDBC::SQLDBC_Statement::execute | ( | const char * | sql, | |
const SQLDBC_Length | sqlLength, | |||
const SQLDBC_StringEncoding | encoding | |||
) | [inherited] |
Executes an UNICODE/ASCII coded SQL statement.
The SQL statement is executed immediately on sending a DBS request to the database. In case of an error, the SQLDBC_ErrorHndl object (to be queried using error()) of this object is set. If the executed SQL statement is a query, a result set is created. The application can check this using isQuery(), and obtain retrieve the ResultSet using getResultSet().
sql | The SQL statement to be executed. The coding of this string argument depends from the encoding argument. | |
sqlLength | The length in bytes of the of the SQL statement | |
encoding | The character coding of the SQL statement |
SQLDBC_Retcode SQLDBC::SQLDBC_Statement::execute | ( | const char * | sql, | |
const SQLDBC_StringEncoding | encoding | |||
) | [inherited] |
Executes an UNICODE/ASCII coded zero-terminated SQL statement.
The SQL statement is executed immediately on sending a DBS request to the database. In case of an error, the SQLDBC_ErrorHndl object (to be queried using error()) of this object is set. If the executed SQL statement is a query, a result set is created. The application can check this using isQuery(), and obtain retrieve the resultset using getResultSet().
sql | The zero-terminated SQL statement to be executed. The coding of this string argument depends from the encoding argument. | |
encoding | The character coding of the SQL statement. |
SQLDBC_Retcode SQLDBC::SQLDBC_Statement::execute | ( | const char * | sql | ) | [inherited] |
Executes an ASCII coded zero-terminated SQL statement.
The SQL statement is executed immediately on sending a DBS request to the database. In case of an error, the SQLDBC_ErrorHndl object (to be queried using error()) of this object is set. If the executed SQL statement is a query, a result set is created. The application can check this using isQuery(), and obtain retrieve the resultset using getResultSet().
sql | The zero-terminated ASCII coded SQL statement to be execute. |
void SQLDBC::SQLDBC_Statement::setResultSetFetchSize | ( | SQLDBC_Int2 | rows | ) | [inherited] |
Sets the maximum number of be rows that can be fetched at once.
Sets the maximum number of rows to be fetched from a result set. Use this to manipulate the number of rows in the order interface. Use a value > 0 to set the maximum number of rows. Use a value <= 0 to reset this limit to the default value. The default value is 'unlimited' (32767). Setting this value does not affect an already executed SQL statement.
rows | [in] Number of Rows to be fetched. |
void SQLDBC::SQLDBC_Statement::setMaxRows | ( | SQLDBC_UInt4 | rows | ) | [inherited] |
Limits the number of rows of an SQLDBC_ResultSet object.
The number of rows of the result set is truncated if the result of a query statement is larger than this limit. The default setting is 'unlimited' (0). Setting this limit does not affect an already executed SQL statement.
rows | [in] Maximum number of rows of a result set |
const SQLDBC_UInt4 SQLDBC::SQLDBC_Statement::getMaxRows | ( | ) | const [inherited] |
Returns the maximum number of rows allowed in a result set.
This value may be set with setMaxRows before the execution of an SQL statement.
SQLDBC_ResultSet* SQLDBC::SQLDBC_Statement::getResultSet | ( | ) | [inherited] |
Retrieves a reference to the SQLDBC_ResultSet object.
void SQLDBC::SQLDBC_Statement::setCursorName | ( | const char * | buffer, | |
SQLDBC_Length | bufferLength, | |||
const SQLDBC_StringEncoding | encoding | |||
) | [inherited] |
Sets the cursor name.
Setting the cursorname affects only query and database procedure commands. For DDL-, INSERT-, UPDATE- and DELETE- commands setting the cursorname has no effect.
buffer | The new cursor name. | |
bufferLength | Length in bytes of the buffer. In case a zero-terminated string passed on in the buffer argument, you can set the bufferLength to SQLDBC_NTS. | |
encoding | Encoding of the cursor name. |
SQLDBC_Retcode SQLDBC::SQLDBC_Statement::setCommandInfo | ( | const char * | buffer, | |
SQLDBC_Length | bufferLength, | |||
SQLDBC_Int4 | lineNumber | |||
) | [inherited] |
Sets the command info.
Sets the command info and a line number (for example name of programm and current line number). This will be send to the database kernel as part of a parse order. If the kernel runs in a special diagnose mode these information will be stored in a system table and can be used to profile your application. The column info and line number will be unset after the next execute of a SQL command at this statement handle.
buffer | The command info. | |
bufferLength | Length in bytes of the buffer. In case a zero-terminated string passed on in the buffer argument, you can set the bufferLength to SQLDBC_NTS. Set bufferLength to SQLDBC_NULL_DATA if you want to unset the command info and line number. | |
lineNumber | The line number. |
SQLDBC_Retcode SQLDBC::SQLDBC_Statement::getCursorName | ( | char * | buffer, | |
const SQLDBC_StringEncoding | encoding, | |||
const SQLDBC_Length | bufferSize, | |||
SQLDBC_Length * | bufferLength | |||
) | const [inherited] |
Retrieves the cursor name.
The cursor name may be set by:
buffer | The buffer into which the zero-terminated cursor name is copied. | |
encoding | Encoding of the buffer where the cursor name is stored. | |
bufferSize | Maximum size of the buffer in bytes. | |
bufferLength | [out] Number of bytes copied to the buffer, except the number of bytes necessary for the zero-terminator. If the source string exceeds the bufferSize. SQLDBC_DATA_TRUNC will be returned and the bufferLength set to the number of bytes (except terminator bytes) needed to copy without truncation. |
SQLDBC_Retcode SQLDBC::SQLDBC_Statement::getTableName | ( | char * | buffer, | |
const SQLDBC_StringEncoding | encoding, | |||
const SQLDBC_Length | bufferSize, | |||
SQLDBC_Length * | bufferLength | |||
) | const [inherited] |
Retrieves the table name (for SELECT FOR UPDATE commands).
buffer | The buffer in which into the table name is copied. | |
encoding | Encoding of the buffer where the table name is stored. | |
bufferSize | Size (in bytes) of the buffer | |
bufferLength | [out] Number of bytes copied to the buffer, except the number of bytes necessary for the zero-terminator. If the source string exceeds the bufferSize value SQLDBC_DATA_TRUNC will be returned and the bufferLength set to the number of bytes (except the terminator bytes) needed to copy the table name without truncation. |
SQLDBC_Bool SQLDBC::SQLDBC_Statement::isQuery | ( | ) | const [inherited] |
Checks if the SQL statement is a query.
A statement is a query only if it returns a result set. This can be determined only after execution of the statement object.
const SQLDBC_Int4 SQLDBC::SQLDBC_Statement::getRowsAffected | ( | ) | const [inherited] |
Returns the number of rows affected by the executed SQL statement.
This method returns a non-zero value if more than one row was addressed by the SQL statement. If the return value is lower than zero, more than one rows was addressed but the exact number of addressed rows cannot be determined.
void SQLDBC::SQLDBC_Statement::setResultSetType | ( | ResultSetType | type | ) | [inherited] |
Sets the type of a result set.
A result set is only created by a query command.
There are three kind of result sets:
type | [in] The result set type. Possible values are: FORWARD_ONLY, SCROLL_SENSITIVE, SCROLL_INSENSITIVE (default) |
const ResultSetType SQLDBC::SQLDBC_Statement::getResultSetType | ( | ) | const [inherited] |
Returns the type of a result set.
If the requested result set type isn't allowed for this SQL statement, the SQLDBC changes it to an allowed one. Check this with getResultSetType() if the execute() member function returns with a warning.
void SQLDBC::SQLDBC_Statement::setResultSetConcurrencyType | ( | ConcurrencyType | type | ) | [inherited] |
Sets the type of the result set concurrency There are two kinds of concurrency:
type | [in] The result set type. Possible values are: CONCUR_READ_ONLY (default) CONCUR_UPDATABLE |
const ConcurrencyType SQLDBC::SQLDBC_Statement::getResultSetConcurrencyType | ( | ) | const [inherited] |
Retrieves the type of the result set concurrency There are two kinds of concurrency:
const SQLDBC_Int4* SQLDBC::SQLDBC_Statement::getRowStatus | ( | ) | const [inherited] |
Returns the row status array.
The row status array describes the state of each row. The size of the row status array is increased by each addBatch() function call.
const SQLDBC_UInt4 SQLDBC::SQLDBC_Statement::getBatchSize | ( | ) | const [inherited] |
Returns the size of the row status array.
const SQLDBC_Retcode SQLDBC::SQLDBC_Statement::addBatch | ( | const char * | sql, | |
SQLDBC_Length | sqlLength, | |||
SQLDBC_StringEncoding | encoding | |||
) | [inherited] |
Adds a statement to the batch.
Statements for batched execution must not return result sets.
sql | The statement to be added | |
sqlLength | Length in Bytes of the statement | |
encoding | Encoding of the statement |
const SQLDBC_Retcode SQLDBC::SQLDBC_Statement::addBatch | ( | const char * | sql, | |
SQLDBC_StringEncoding | encoding | |||
) | [inherited] |
Adds a statement to the batch.
The must be end with a zero-terminator.
sql | The statement to be added | |
encoding | Encoding of the statement |
const SQLDBC_Retcode SQLDBC::SQLDBC_Statement::addBatch | ( | const char * | sql | ) | [inherited] |
Adds a statement to the batch.
The must be end with a zero-terminator and in ASCII code.
sql | The statement to be added |
const SQLDBC_Retcode SQLDBC::SQLDBC_Statement::executeBatch | ( | ) | [inherited] |
Executes the statements previously input via addBatch().
void SQLDBC::SQLDBC_Statement::clearBatch | ( | ) | [inherited] |
Clears the array of batched statements.
SQLDBC_Retcode SQLDBC::SQLDBC_Statement::getLastInsertedKey | ( | SQLDBC_Int4 | tag, | |
SQLDBC_HostType | type, | |||
void * | paramAddr, | |||
SQLDBC_Length * | lengthIndicator, | |||
SQLDBC_Length | size, | |||
SQLDBC_Bool | terminate = SQLDBC_TRUE | |||
) | [inherited] |
Retrieves the key that was inserted by the last insert operation.
tag | The tag that describes whether to get the last or the first serial key. One of SQLDBC_FIRST_INSERTED_SERIAL , SQLDBC_LAST_INSERTED_SERIAL . | |
type | The output host type. | |
paramAddr | The parameter address. | |
lengthIndicator | The length or indicator value. | |
size | The size of the output parameter, in bytes. | |
terminate | Whether output strings are terminated. Default is SQLDBC_TRUE . |
SQLDBC_OK
, if the value is returned, SQLDBC_NOT_OK
if an error is set, SQLDBC_NO_DATA_FOUND
if the statement didn't inserted any key, or didn't report them to the interface. void SQLDBC::SQLDBC_Statement::clearResultSet | ( | ) | [protected, inherited] |
SQLDBC_ErrorHndl& SQLDBC::SQLDBC_ConnectionItem::error | ( | ) | [inherited] |
Returns a reference to the ErrorHndl object.
void SQLDBC::SQLDBC_ConnectionItem::clearError | ( | ) | [inherited] |
Deletes the error has been stored.
SQLDBC_SQLWarning* SQLDBC::SQLDBC_ConnectionItem::warning | ( | ) | [inherited] |
Returns a reference to an SQLWarning object stored in the SQLDBC_ConnectionItem object.
void SQLDBC::SQLDBC_ConnectionItem::clearWarnings | ( | ) | [inherited] |
Deletes the warning stored in the SQLWarning object.