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From: gordon@mead.UUCP (Gordon Edwards)
Newsgroups: comp.databases
Subject: Ingres ESQL question.
Message-ID: <1269@meaddata.mead.UUCP>
Date: 4 Sep 90 20:26:07 GMT
Sender: usenet@mead.UUCP
Reply-To: mead!gordon@uccba.uc.edu
Distribution: comp
Organization: Mead Data Central, Dayton OH
Lines: 65

According to the ESQL documentation the statement_name in PREPARE can be a
string constant or a host string variable.

This works:

	char dsql[100];

	strcpy(dsql, "select a, b from y");

	EXEC SQL PREPARE s FROM :dsql;

This does not:

	char dsql[100];
	char *s;

	strcpy(dsql, "select a, b from y");

	EXEC SQL PREPARE :s FROM :dsql;

I did a similar thing for declaring cursors as host string variables (see
the test program below) which worked.  There are no examples of statement_
name as a host string variable.

Has anyone ever used this construct?  Would an Ingres person like to comment?

Below is the entire test program:

EXEC SQL INCLUDE sqlca;

main()
{
	EXEC SQL BEGIN DECLARE SECTION;
	int a_val, b_val;
	char *c, *s;
	char dsql[100];
	EXEC SQL END DECLARE SECTION;

	EXEC SQL CONNECT 'iilibdb';

	strcpy(dsql, "select a, b from y");

	EXEC SQL PREPARE :s FROM :dsql;
			 ^^ works if just ... PREAPRE s FROM ...

	EXEC SQL DECLARE :c CURSOR FOR :s;
				       ^^ works if just ... FOR s;

	EXEC SQL OPEN :c;

	do {
		EXEC SQL FETCH :c INTO :a_val, :b_val;

		printf("\ta = %d\tb = %d\n", a_val, b_val);
	} while (sqlca.sqlcode == 0);

	EXEC SQL CLOSE :c;
	
	EXEC SQL DISCONNECT;
}

Thanks.

--
Gordon Edwards                                    Mead Data Central, Dayton OH