SQLGetPosition - Return starting position of string

 

SQLGetPosition() is used to return the starting position of one string within a LOB value (the source). The source value must be a LOB locator; the search string can be a LOB locator or a literal string.

The source and search LOB locators can be any that have been returned from the database from a fetch or an SQLGetSubString() call during the current transaction.

 

Syntax

SQLRETURN   SQLGetPosition   (SQLHSTMT          StatementHandle,   
                              SQLSMALLINT       LocatorCType,
                              SQLINTEGER        SourceLocator,
                              SQLINTEGER        SearchLocator,
                              SQLCHAR           *SearchLiteral,
                              SQLINTEGER        SearchLiteralLength,
                              SQLINTEGER        FromPosition,
                              SQLINTEGER        *LocatedAt,
                              SQLINTEGER        *IndicatorValue);

 

Function arguments

Table 1. SQLGetPosition arguments
Data type Argument Use Description
SQLHSTMT StatementHandle Input Statement handle. This can be any statement handle which has been allocated but which does not currently have a prepared statement assigned to it.
SQLSMALLINT LocatorCType Input The C type of the source LOB locator. This can be:

  • SQL_C_BLOB_LOCATOR

  • SQL_C_CLOB_LOCATOR

  • SQL_C_DBCLOB_LOCATOR
SQLINTEGER SourceLocator Input SourceLocator must be set to the source LOB locator.
SQLINTEGER SearchLocator Input If the SearchLiteral pointer is NULL and if SearchLiteralLength is set to 0, then SearchLocator must be set to the LOB locator associated with the search string; otherwise, this argument is ignored.
SQLCHAR * SearchLiteral Input This argument points to the area of storage that contains the search string literal.

If SearchLiteralLength is 0, this pointer must be NULL.

SQLINTEGER SearchLiteralLength Input The length of the string in SearchLiteral(in bytes).1

If this argument value is 0, then the argument SearchLocator is meaningful.

SQLINTEGER FromPosition Input For BLOBs and CLOBs, this is the position of the first byte within the source string at which the search is to start. to be returned by the function. For DBCLOBs, this is the first character. The start byte or character is numbered 1.
SQLINTEGER * LocatedAt Output For BLOBs and CLOBs, this is the byte position at which the string is located or, if not located, the value zero. For DBCLOBs, this is the character position.

If the length of the source string is zero, the value 1 is returned.

SQLINTEGER * IndicatorValue Output Always set to zero.

1. This is in bytes even for DBCLOB data.

 

Usage

SQLGetPosition() is used in conjunction with SQLGetSubString() in order to obtain any portion of a string in a random manner. In order to use SQLGetSubString(), the location of the substring within the overall string must be known in advance. In situations where the start of that substring can be found by a search string, SQLGetPosition() can be used to obtain the starting position of that substring.

The Locator and SearchLocator (if used) arguments can contain any valid LOB locator which has not been explicitly freed using a FREE LOCATOR statement or implicitly freed because the transaction during which it is created has terminated.

The Locator and SearchLocator must have the same LOB locator type.

The statement handle must not have been associated with any prepared statements or catalog function calls.

 

Return codes

 

Error conditions

Table 2. SQLGetPosition SQLSTATEs
SQLSTATE Description Explanation
07006 Conversion that is not valid The combination of the LocatorCType argument and either of the LOB locator values is not valid.
0F001 LOB variable that is not valid The value specified for argument Locator or SearchLocator is not currently a LOB locator.
42818 Length that is not valid The length of the pattern is too long.
58004 Unexpected system failure Unrecoverable system error.
HY009 Argument value that is not valid The argument LocatedAt or IndicatorValue is a null pointer.

The argument value for FromPosition is not greater than 0.

LocatorCType is not one of SQL_C_CLOB_LOCATOR, SQL_C_BLOB_LOCATOR, or SQL_C_DBCLOB_LOCATOR.

HY010 Function sequence error The specified StatementHandle argument is not in an allocated state.
HY021 Internal descriptor that is not valid The internal descriptor cannot be addressed or allocated, or it contains a value that is not valid.
HY090 String or buffer length that is not valid The value of SearchLiteralLength is less than 1, and not SQL_NTS.
HYC00 Driver not capable The application is currently connected to a data source that does not support large objects.

 

Restrictions

This function is not available when connected to a DB2® server that does not support Large Objects.

 

References

 

Parent topic:

DB2 UDB CLI functions