Determining how many SQLVAR occurrences are needed

The number of SQLVAR occurrences needed depends on the statement that the SQLDA was provided for and the data types of the columns or parameters being described.

If the USING BOTH clause was not specified for the statement and neither LOBs nor distinct types are present in the result, only one SQLVAR entry (a base entry) is needed for each column. The 7th byte of SQLDAID is set to a space. The SQLD is set to the number of columns in the result and represents the number of SQLVAR occurrences needed. If an insufficient number of SQLVAR occurrences were provided, DB2® returns a +236 warning in SQLCODE if the standards option was set. Otherwise, SQLCODE is zero.

If USING BOTH is specified and neither LOBs nor distinct types are present in the result, an extended SQLVAR entry per column is needed for the labels in addition to the base SQLVAR entry. The 7th byte of the SQLDAID is set to space. SQLD is set to the twice the number of columns in the result and represents the combined number of base and extended SQLVAR occurrences needed.

If LOBs, distinct types, or both are present in the results, one extended SQLVAR entry is needed per column in addition to the base SQLVAR entry with one exception. The exception is that when the USING BOTH clause is specified and distinct types are present in the results, two extended SQLVAR entries per column are needed. When a sufficient number of SQLVAR entries are provided in the SQLDA for both the base and extended SQLVARs, information for the LOBs and distinct types is returned. The 7th byte of SQLDAID is set to the number of SQLVAR entries that were used for each column:

2: Two SQLVAR entries per column (a base and an extended)
3: Three SQLVAR entries per column (a base and two extended)

SQLD is set to the number of columns in the result. Therefore, the value of the 7th byte of SQLDAID multiplied by the value of SQLD is the total number SQLVAR entries that were provided.

Otherwise, when an insufficient number of SQLVAR entries have been provided when LOBs or distinct types are present, DB2 indicates that by returning one of the following warnings in SQLCODE. DB2 also sets the 7th byte of SQLDAID to indicate how many SQLVAR entries are needed for each column of the result.

+237: There are insufficient SQLVAR entries to describe the data, and the data includes distinct types. In this case, there were enough base SQLVAR entries to describe the data, so the base SQLVAR entries are set. However, sufficient extended SQLVAR entries were not provided so the distinct type names are not returned.
+238: There are insufficient SQLVAR entries to describe the data, and the data includes LOBs. In this case no information is returned in the SQLVAR entries.
+239: There are insufficient SQLVAR entries to describe the data, and the data includes distinct types. There weren't even enough base SQLVAR entries. In this case no information is returned in the SQLVAR entries.