isCOBOL Evolve : Language Reference : Embedded SQL (ESQL) : SQLDA
SQLDA
A SQLDA (SQL Descriptor Area) is a collection of variables that are required for execution of the SQL DESCRIBE statement, and can optionally be used by the PREPARE, OPEN, FETCH, EXECUTE, and CALL statements.
SQLDA is supported only in compatibility with IBM DB2 and can be used only on the IBM DB2 database.
In order to enable the compatibility with IBM DB2, the esql.db2 compiler directive must be set to '1', 'on', 'true' or 'yes'. The setting can be done either in the source file, by adding the following line above IDENTIFICATION DIVISION:
$SET "esql.db2" "1"
or via the Compiler configuration, by setting:
iscobol.compiler.esql.db2=1
SQLDA has the following structure, that should be added to the Working-Storage Section of the program:
      *****************************************************
      * SQL DESCRIPTOR AREA *
      *****************************************************
       01 SQLDA.
          02 SQLDAID PIC X(8) VALUE 'SQLDA '.
          02 SQLDABC PIC S9(8) COMPUTATIONAL VALUE 33016.
          02 SQLN PIC S9(4) COMPUTATIONAL VALUE 750.
          02 SQLD PIC S9(4) COMPUTATIONAL VALUE 0.
          02 SQLVAR OCCURS 1 TO 750 TIMES DEPENDING ON SQLN.
             03 SQLTYPE PIC S9(4) COMPUTATIONAL.
             03 SQLLEN PIC S9(4) COMPUTATIONAL.
             03 SQLDATA POINTER.
             03 SQLIND POINTER.
             03 SQLNAME.
                49 SQLNAMEL PIC S9(4) COMPUTATIONAL.
                49 SQLNAMEC PIC X(30).
SQLDA fields are set by the database manager after a DESCRIBE or a PREPARE statement and they have the following meaning.
SQLDAID
Contains the string 'SQLDA '
SQLDABC
Length of the SQLDA
SQLN
Unchanged in this context
SQLD
Number of columns described by occurrences of SQLVAR
SQLTYPE
The data type of the column.
See SQLTYPE values below for the list of possible values
SQLLEN
The length attribute of the column
SQLDATA
Not used
SQLIND
Not used
SQLNAME
The unqualified name of the column.
This is a varchar field: SQLNAMEL contains the length of the value, while SQLNAMEC contains the value.
SQLDA fields can also set by the user prior to executing a FETCH statement, an OPEN statement, a CALL statement or an EXECUTE statement. In these cases they have the following meaning.
SQLDAID
Contains the string 'SQLDA '
SQLDABC
Length of the SQLDA
SQLN
Total number of occurrences of SQLVAR provided in the SQLDA
SQLD
Number of occurrences of SQLVAR entries in the SQLDA that are used when executing the statement. It must be set to a value greater than or equal to zero and less than or equal to SQLN
SQLTYPE
The data type of the host variable and whether an indicator variable is provided.
See SQLTYPE values below for the list of possible values
SQLLEN
The length attribute of the host variable
SQLDATA
Contains the address of the host variable
SQLIND
Contains the address of the indicator variable. It’s ignored if there is no indicator variable (as indicated by an even value of SQLTYPE)
SQLNAME
Not used
Note - due to the presence of POINTER data items that can be reused and included in arithmetic expressions, programs including SQLDA should be compiled with the -cp option and, if you’re on a 64-bit platform, with -d64 option as well.
SQLTYPE values
Value without indicator
Value with indicator
Type
384
385
Date
388
389
Time
392
393
Timestamp
396
397
DataLink
404
405
BLOB
408
409
CLOB
412
413
DBCLOB
448
449
Varying-length character string
452
453
Fixed-length character string
456
457
Long varying-length character string
480
481
Floating point
484
485
Packed decimal
488
489
Zoned decimal
492
493
Big integer
496
497
Large integer
500
501
Small integer
904
905
ROWID
908
909
Varying-length binary string
912
913
Fixed-length binary string
988
989
XML