SQL_GET_COLUMN_DATA_SIZE¶

Applies to: SQLFlex

This command is used to get the size of the data in a column retrieved through an embedded SQL statement. By passing the column number the size of the data in the column will be put into the specified variable. The size returned will be the smaller of the actual size of the data or the SQL_SET_MAX_DATA_SIZE setting. So for instance, if the data stored in a column is 64MB, but the SQL_SET_MAX_DATA_SIZE is set to 16MB, then this command will return 16MB. Note that you may need to use Set_Argument_Size to allow for a large chunk size because the default maximum string size in most modern dataflex versions is only 64KB.

Syntax

SQL_GET_COLUMN_DATA_SIZE COLUMN {column} to {variable}

Parameter

Description

column

Column number to get chunk from

variable

Variable to hold the returned data size

Example

SQL_SET_MAX_DATA_SIZE to |CI$4000000 //(64MB)
move |CI$80000 to iChunkSize // 512KB
SQL_SET_CHUNK_SIZE to iChunkSize

SQL_SET_STMT to "SELECT * FROM CUSTOMER WHERE STATUS = 'Active' "
SQL_PREPARE_STMT
SQL_EXECUTE_STMT
SQL_FETCH_NEXT_ROW into sID sBio
If (Found) Begin
    SQL_GET_COLUMN_DATA_SIZE COLUMN 6 to iDataSize

    Repeat
        SQL_GET_DATA_CHUNK COLUMN 6 OFFSET iProgress to sChunk
        ADD iChunkSize to iProgress
        write sChunk
    until (iProgress >= iDataSize)

End

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