The typed row variable

A typed row variable specifies a field list, which contains the name and data type of each field in the row.

The following figure shows declarations for three typed row variables.
Figure 1. Sample typed row variables
EXEC SQL BEGIN DECLARE SECTION;
  row (circle_vals circle_t, circle_id integer) mycircle;
  row (a char(20), 
      b set(integer not null),
      c decimal(10,2)) row2;
  row (x integer,
      y integer,
      length integer,
      width integer) myrect;
EXEC SQL END DECLARE SECTION;
Typed row variables can contain fields with the following data types:
  • Any built-in data type (such as INTEGER, CHAR, BOOLEAN, and FLOAT) except BYTE, TEXT, SERIAL, or SERIAL8.
  • Collection data types, such as SET and LIST
  • Row types, named or unnamed
  • Opaque data types
When you specify the type of a field in the row variable, use SQL data types, not IBM® Informix® ESQL/C data types. For example, to declare a row variable with a field that holds small integers, use the SQL SMALLINT data type, not the Informix ESQL/C int data type. Similarly, to declare a field whose values are character strings, use the SQL syntax for a CHAR column, not the C syntax for char variables. For example, the following declaration of the row_var host variable contains a field of small integers and a character field: 
row (
   smint_fld smallint,
   char_fld char(20)
   ) row_var;

Use a typed row variable when you know the exact data type of the row-type column that you store in the row variable. Match the declaration of a typed row variable exactly with the data type of the row-type column. You can use this row variable directly in SQL statements such as INSERT, DELETE, or UPDATE. You can also use it in the collection-derived table clause.

You can declare several row variables in a single declaration line. However, all variables must have the same field types, as the following declaration shows: 
EXEC SQL BEGIN DECLARE SECTION;
   row (x integer, y integer) typed_row1, typed_row2;
EXEC SQL END DECLARE SECTION;

If you do not know the exact data type of the row-type column you want to access, use an untyped row variable.