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ESQL elements and statements
Syntax
Example
338
OPEN
Executes a prepared SQL query associated with a cursor and creates a result set composed of
the rows that satisfy the query. This set of rows is called the active set.
OPEN cursor_name
[ USING { [ SQL ] DESCRIPTOR structure_name
| :host_variable [ [ INDICATOR ] :ind_variable ] , ... } ] ;
cursor_name
An identifier named in an earlier DECLARE CURSOR statement.
USING [ SQL ] DESCRIPTOR structure_name
Directs the SQL engine to create the result set in storage addressed by the identified
SQLDA structure.
USING :host_variable [ [ INDICATOR ] :ind_variable ]
Directs the SQL engine to create the result set in storage addressed by host variables.
/*
** 5. Name WHENEVER routine to handle SQLERROR.
**
** 6. DECLARE cursor for the SELECT statement.
** NOTE: You must set input parameter values before OPEN CURSOR.
** The static query in this program does not have input parameters.
**
** 7. OPEN the cursor.
** NOTE: For static statements, if a DECLARE CURSOR
** statement contains references to automatic variables,
** the OPEN CURSOR statement must be in the same C function.
**
** 8. Name WHENEVER routine to handle NOT FOUND condition.
*/
EXEC SQL WHENEVER SQLERROR GOTO selerr ;
EXEC SQL DECLARE stcur CURSOR FOR
SELECT InvTransNum, Qty,
OrderNum FROM PUB.InventoryTrans ;
EXEC SQL OPEN stcur ;
EXEC SQL WHENEVER NOT FOUND GOTO seldone ;
Notes • Executing an OPEN cursor statement sets the cursor to the open state.
• After the OPEN cursor statement is executed, the cursor is positioned just before the first
row of the active set.
• For a single execution of an OPEN cursor statement, the active set does not change and the
host variables are not re-examined.
• If you elect to retrieve a new active set and a host variable value has changed, you must
CLOSE the cursor and OPEN it again.