Updated on 2023-12-29 GMT+08:00

SQLColAttribute

Function

SQLColAttribute returns the descriptor information about a column in the result set.

Prototype

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SQLRETURN SQLColAttribute(SQLHSTMT        StatementHandle,    
                          SQLUSMALLINT    ColumnNumber,     
                          SQLUSMALLINT    FieldIdentifier,
                          SQLPOINTER      CharacterAtrriburePtr,
                          SQLSMALLINT     BufferLength,
                          SQLSMALLINT     *StringLengthPtr,
                          SQLPOINTER      NumericAttributePtr);

Parameter

Table 1 SQLColAttribute parameter

Keyword

Description

StatementHandle

Statement handle.

ColumnNumber

Column number of the field to be queried, starting at 1 and increasing in an ascending order.

FieldIdentifier

Field identifier of ColumnNumber in IRD.

CharacterAttributePtr

Output parameter: pointer to the buffer that returns FieldIdentifier field value.

BufferLength

  • FieldIdentifier indicates the length of the buffer if FieldIdentifier is an ODBC-defined field and CharacterAttributePtr points to a character string or a binary buffer.
  • Ignore this parameter if FieldIdentifier is an ODBC-defined field and CharacterAttributePtr points to an integer.

StringLengthPtr

Output parameter: pointer to a buffer in which the total number of valid bytes (for string data) is stored in *CharacterAttributePtr. Ignore the value of BufferLength if the data is not a string.

NumericAttributePtr

Output parameter: pointer to an integer buffer in which the value of the FieldIdentifier field in the ColumnNumber row of the IRD is returned.

Return Values

  • SQL_SUCCESS indicates that the call succeeded.
  • SQL_SUCCESS_WITH_INFO indicates some warning information is displayed.
  • SQL_ERROR indicates major errors, such as memory allocation and connection failures.
  • SQL_INVALID_HANDLE indicates that invalid handles were called. Values returned by other APIs are similar to the preceding values.

Precautions

If SQLColAttribute returns SQL_ERROR or SQL_SUCCESS_WITH_INFO, the application can then call SQLGetDiagRec, set HandleType and Handle to SQL_HANDLE_STMT and StatementHandle, and obtain the SQLSTATE value. The SQLSTATE value provides the detailed function calling information.

Examples

See Examples.