From 4140c2f30e2814527f0975876956f446e326ae70 Mon Sep 17 00:00:00 2001
From: "Thomas G. Lockhart" <lockhart@fourpalms.org>
Date: Mon, 14 Dec 1998 00:02:17 +0000
Subject: Add support for the CASE statement in the rewrite handling. Allows
 (at least some) rules and views. Still some trouble (crashes) with target
 CASE columns spanning tables,  but lots now works.

---
 src/backend/nodes/readfuncs.c | 50 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 49 insertions(+), 1 deletion(-)

(limited to 'src/backend/nodes/readfuncs.c')

diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index c915ed6ed74..a6650efecf1 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.39 1998/11/22 10:48:40 vadim Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.40 1998/12/14 00:01:47 thomas Exp $
  *
  * NOTES
  *	  Most of the read functions for plan nodes are tested. (In fact, they
@@ -786,6 +786,50 @@ _readExpr()
 	return local_node;
 }
 
+/* ----------------
+ *		_readCaseExpr
+ *
+ *	CaseExpr is a subclass of Node
+ * ----------------
+ */
+static CaseExpr *
+_readCaseExpr()
+{
+	CaseExpr   *local_node;
+	char	   *token;
+	int			length;
+
+	local_node = makeNode(CaseExpr);
+
+	local_node->args = nodeRead(true);
+	token = lsptok(NULL, &length);		/* eat :default */
+	local_node->defresult = nodeRead(true);
+
+	return local_node;
+}
+
+/* ----------------
+ *		_readCaseWhen
+ *
+ *	CaseWhen is a subclass of Node
+ * ----------------
+ */
+static CaseWhen *
+_readCaseWhen()
+{
+	CaseWhen   *local_node;
+	char	   *token;
+	int			length;
+
+	local_node = makeNode(CaseWhen);
+
+	local_node->expr = nodeRead(true);
+	token = lsptok(NULL, &length);		/* eat :then */
+	local_node->result = nodeRead(true);
+
+	return local_node;
+}
+
 /* ----------------
  *		_readVar
  *
@@ -2037,6 +2081,10 @@ parsePlanString(void)
 		return_value = _readSortClause();
 	else if (!strncmp(token, "GROUPCLAUSE", length))
 		return_value = _readGroupClause();
+	else if (!strncmp(token, "CASE", length))
+		return_value = _readCaseExpr();
+	else if (!strncmp(token, "WHEN", length))
+		return_value = _readCaseWhen();
 	else
 		elog(ERROR, "badly formatted planstring \"%.10s\"...\n", token);
 
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