Specification: | DB2 CLI 2.1 |
SQLBindFileToParam() is used to associate (bind) a parameter marker in an SQL statement to a file reference or an array of file references. This enables data from the file to be transferred directly into a LOB column when that statement is subsequently executed.
The LOB file reference arguments (file name, file name length, file reference options) refer to a file within the application's environment (on the client). Before calling SQLExecute() or SQLExecDirect(), the application must make sure that this information is available in the deferred input buffers. These values can be changed between SQLExecute() calls.
Syntax
SQLRETURN SQLBindFileToParam (SQLHSTMT StatementHandle, SQLUSMALLINT TargetType, SQLSMALLINT DataType, SQLCHAR *FAR FileName, SQLSMALLINT *FAR FileNameLength, SQLUINTEGER *FAR FileOptions, SQLSMALLINT MaxFileNameLength, SQLINTEGER *FAR IndicatorValue);
Function Arguments
Table 19. SQLBindFileToParam Arguments
Data Type | Argument | Use | Description |
---|---|---|---|
SQLHSTMT | StatementHandle | input | Statement handle. |
SQLUSMALLINT | TargetType | input | Parameter marker number. Parameters are numbered sequentially, from left to right, starting at 1. |
SQLSMALLINT | DataType | input | SQL Data Type of the column. The data type must be one of:
|
SQLCHAR * | FileName | input (deferred) | Pointer to the location that will contain the file name or an array of
file names when the statement (StatementHandle) is executed.
This is either the complete path name of the file or a relative file
name. If a relative file name is provided, it is appended to the
current path of the client process.
This argument cannot be NULL. |
SQLSMALLINT * | FileNameLength | input (deferred) | Pointer to the location that will contain the length of the file name (or
an array of lengths) at the time of the next SQLExecute() or SQLExecDirect() using the
StatementHandle.
If this pointer is NULL, then a length of SQL_NTS is assumed. The maximum value of the file name length is 255. |
SQLUINTEGER * | FileOptions | input (deferred) | Pointer to the location that will contain the file option (or an array of
file options) to be used when reading the file. The location will be
accessed when the statement (StatementHandle) is executed.
Only one option is supported (and it must be specified):
This pointer cannot be NULL. |
SQLSMALLINT | MaxFileNameLength | input | This specifies the length of the FileName buffer. If the application calls SQLParamOptions() to specify multiple values for each parameter, this is the length of each element in the FileName array. |
SQLINTEGER * | IndicatorValue | output (deferred) | Pointer to the location that contains an indicator value (or array of values), which is set to SQL_NULL_DATA if the data value of the parameter is to be null. It must be set to 0 (or the pointer can be set to null) when the data value is not null. |
Usage
The application calls SQLBindFileToParam() once for each parameter marker whose value should be obtained directly from a file when a statement is executed. Before the statement is executed, FileName, FileNameLength, and FileOptions values must be set. When the statement is executed, the data for any parameter which has been bound using SQLBindFIleToParam() is read from the referenced file and passed to the server.
If the application uses SQLParamOptions() to specify multiple values for each parameter, then FileName, FileNameLength, and FileOptions point to an array of LOB file reference variables. In this case, MaxFileNameLength specifies the length of each element in the FileName array and is used by DB2 CLI to determine the location of each element in the FileName array.
A LOB parameter marker can be associated with (bound to) an input file using SQLBindFileToParam(), or with a stored buffer using SQLBindParameter(). The most recent bind parameter function call determines the type of binding that is in effect.
Return Codes
Diagnostics
Table 20. SQLBindFileToParam SQLSTATEs
SQLSTATE | Description | Explanation |
---|---|---|
40003 08S01 | Communication link failure. | The communication link between the application and data source failed before the function completed. |
58004 | Unexpected system failure. | Unrecoverable system error. |
HY001 | Memory allocation failure. | DB2 CLI is unable to allocate memory required to support execution or completion of the function. |
HY004 | SQL data type out of range. | The value specified for DataType was not a valid SQL type for this function call. |
HY009 | Invalid argument value. | FileName, FileOptions FileNameLength, is a null pointer. |
HY010 | Function sequence error. | The function was called while in a data-at-execute (SQLParamData(), SQLPutData()) operation.
The function was called while within a BEGIN COMPOUND and END COMPOUND SQL operation. |
HY013 | Unexpected memory handling error. | DB2 CLI was unable to access memory required to support execution or completion of the function. |
HY090 | Invalid string or buffer length. | The value specified for the input argument MaxFileNameLength was less than 0. |
HY093 | Invalid parameter number. | The value specified for TargetType was either less than 1 or greater than the maximum number of parameters supported. |
HYC00 | Driver not capable. | The server does not support Large Object data types. |
Restrictions
This function is not available when connected to DB2 servers that do not support Large Object data types. Call SQLGetFunctions() with the function type set to SQL_API_SQLBINDFILETOPARAM and check the SupportedPtr output argument to determine if the function is supported for the current connection.
(The complete sample dtlob.c is also available here .)
/* From the CLI sample dtlob.c */ /* ... */ /* bind the file-parameter */ rc = SQLBindFileToParam(hstmt, 3, SQL_BLOB, fileName, &fileNameLength, &fileOption, 14, &fileInd);
References