first commit for openGauss connect odbc code

columninfo.h

@@ -0,0 +1,54 @@
+/* File:			columninfo.h
+ *
+ * Description:		See "columninfo.c"
+ *
+ * Comments:		See "readme.txt" for copyright and license information.
+ *
+ */
+
+#ifndef __COLUMNINFO_H__
+#define __COLUMNINFO_H__
+
+#include "psqlodbc.h"
+
+#include <libpq-fe.h>
+
+struct ColumnInfoClass_
+{
+	UInt4		refcount;	/* reference count. A ColumnInfo can be shared by
+							 * several qresults. */
+	Int2		num_fields;
+	struct srvr_info
+	{
+		char	*name;		/* field name */
+		OID	adtid;		/* type oid */
+		Int2	adtsize;	/* type size */
+		Int4	display_size;	/* the display size (longest row) */
+		Int4	atttypmod;	/* the length of bpchar/varchar */
+		OID	relid;		/* the relation id */
+		Int2	attid;		/* the attribute number */
+	}	*coli_array;
+};
+
+#define CI_get_num_fields(self)			(self->num_fields)
+#define CI_get_oid(self, col)			(self->coli_array[col].adtid)
+#define CI_get_fieldname(self, col)		(self->coli_array[col].name)
+#define CI_get_fieldsize(self, col)		(self->coli_array[col].adtsize)
+#define CI_get_display_size(self, col)		(self->coli_array[col].display_size)
+#define CI_get_atttypmod(self, col)		(self->coli_array[col].atttypmod)
+#define CI_get_relid(self, col)	(self->coli_array[col].relid)
+#define CI_get_attid(self, col)	(self->coli_array[col].attid)
+
+ColumnInfoClass *CI_Constructor(void);
+void		CI_Destructor(ColumnInfoClass *self);
+void		CI_free_memory(ColumnInfoClass *self);
+BOOL		CI_read_fields_from_pgres(ColumnInfoClass *self, PGresult *pgres);
+
+/* functions for setting up the fields from within the program, */
+/* without reading from a socket */
+void		CI_set_num_fields(ColumnInfoClass *self, int new_num_fields);
+void CI_set_field_info(ColumnInfoClass *self, int field_num, char *new_name,
+		OID new_adtid, Int2 new_adtsize, Int4 atttypmod,
+		OID new_relid, OID new_attid);
+
+#endif