Appendix G: The SQLDA

SQLDA variables and fields

A SQLDA consists of four variables (SQLDAID, SQLDABC, SQLN, and SQLD), followed by an arbitrary number of SQLVARs. A SQLVAR is a structure containing five fields.

The following table describes the SQLDA variables.

**Table G-1: SQLDA variables**
This SQLDA variable:	Performs this function:
SQLDAID	Contains an eye catcher of “SQLDA” for use in storage dumps
SQLDABC	Contains the length of the SQLDA, equal to SQLN*44+16
SQLN	Contains the total number of occurrences of SQLVAR
SQLD	Indicates the number of columns described by occurrences of SQLVAR

Each occurrence of SQLVAR describes one column of the result row you are sending to the client application. The following table describes the five fields that each occurrence of SQLVAR contains.

**Table G-2: SQLDA fields**
This SQLDA field:	Performs this function:
SQLTYPE	Contains a 3-digit value that represents the datatype of the column and whether or not it allows null values. Table G-3 contains the valid datatype values.
SQLLEN	Contains the external length of a value from the column.
SQLDATA	Contains the address of the data being transmitted
SQLIND	Contains the address of an indicator, which tells whether the column is nullable. Use a value less than zero if null.
SQLNAME	Contains the name or label of the column, or a string of length zero if the name or label does not exist.
SQLNAMEL	Contains the length of the column.

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