2026-03-12 20:23:15

timhall/miscellaneous/string_agg.sql

@@ -0,0 +1,87 @@
+-- -----------------------------------------------------------------------------------
+-- File Name    : https://oracle-base.com/dba/miscellaneous/string_agg.sql
+-- Author       : Tim Hall (based on an a method suggested by Tom Kyte).
+--                http://asktom.oracle.com/pls/ask/f?p=4950:8:::::F4950_P8_DISPLAYID:229614022562
+-- Description  : Aggregate function to concatenate strings.
+-- Call Syntax  : Incorporate into queries as follows:
+--                  COLUMN employees FORMAT A50
+--                  
+--                  SELECT deptno, string_agg(ename) AS employees
+--                  FROM   emp
+--                  GROUP BY deptno;
+--                  
+--                      DEPTNO EMPLOYEES
+--                  ---------- --------------------------------------------------
+--                          10 CLARK,KING,MILLER
+--                          20 SMITH,FORD,ADAMS,SCOTT,JONES
+--                          30 ALLEN,BLAKE,MARTIN,TURNER,JAMES,WARD
+--                  
+-- Last Modified: 03-JAN-2018 : Correction to separator handling in ODCIAggregateTerminate
+--                              and ODCIAggregateMerge, suggested by Kim Berg Hansen.
+-- -----------------------------------------------------------------------------------
+CREATE OR REPLACE TYPE t_string_agg AS OBJECT
+(
+  g_string  VARCHAR2(32767),
+
+  STATIC FUNCTION ODCIAggregateInitialize(sctx  IN OUT  t_string_agg)
+    RETURN NUMBER,
+
+  MEMBER FUNCTION ODCIAggregateIterate(self   IN OUT  t_string_agg,
+                                       value  IN      VARCHAR2 )
+     RETURN NUMBER,
+
+  MEMBER FUNCTION ODCIAggregateTerminate(self         IN   t_string_agg,
+                                         returnValue  OUT  VARCHAR2,
+                                         flags        IN   NUMBER)
+    RETURN NUMBER,
+
+  MEMBER FUNCTION ODCIAggregateMerge(self  IN OUT  t_string_agg,
+                                     ctx2  IN      t_string_agg)
+    RETURN NUMBER
+);
+/
+SHOW ERRORS
+
+
+CREATE OR REPLACE TYPE BODY t_string_agg IS
+  STATIC FUNCTION ODCIAggregateInitialize(sctx  IN OUT  t_string_agg)
+    RETURN NUMBER IS
+  BEGIN
+    sctx := t_string_agg(NULL);
+    RETURN ODCIConst.Success;
+  END;
+
+  MEMBER FUNCTION ODCIAggregateIterate(self   IN OUT  t_string_agg,
+                                       value  IN      VARCHAR2 )
+    RETURN NUMBER IS
+  BEGIN
+    SELF.g_string := self.g_string || ',' || value;
+    RETURN ODCIConst.Success;
+  END;
+
+  MEMBER FUNCTION ODCIAggregateTerminate(self         IN   t_string_agg,
+                                         returnValue  OUT  VARCHAR2,
+                                         flags        IN   NUMBER)
+    RETURN NUMBER IS
+  BEGIN
+    returnValue := SUBSTR(SELF.g_string, 2);
+    RETURN ODCIConst.Success;
+  END;
+
+  MEMBER FUNCTION ODCIAggregateMerge(self  IN OUT  t_string_agg,
+                                     ctx2  IN      t_string_agg)
+    RETURN NUMBER IS
+  BEGIN
+    SELF.g_string := SELF.g_string || ctx2.g_string;
+    RETURN ODCIConst.Success;
+  END;
+END;
+/
+SHOW ERRORS
+
+
+CREATE OR REPLACE FUNCTION string_agg (p_input VARCHAR2)
+RETURN VARCHAR2
+PARALLEL_ENABLE AGGREGATE USING t_string_agg;
+/
+SHOW ERRORS