Add test for UNION.

Add additional tests in strings for conversions of the "name" data type.
Test SQL92 string functions such as SUBSTRING() and POSITION().

src/test/regress/sql/strings.sql

@@ -11,13 +11,60 @@ SELECT 'first line'
 -- illegal string continuation syntax
 SELECT 'first line'
 ' - next line' /* this comment is not allowed here */
-' - third line';
+' - third line'
+	AS "Illegal comment within continuation";
 
 --
 -- test conversions between various string types
 --
 
-SELECT text(f1) FROM CHAR_TBL;
+SELECT CAST(f1 AS text) AS "text(char)" FROM CHAR_TBL;
 
-SELECT text(f1) FROM VARCHAR_TBL;
+SELECT CAST(f1 AS text) AS "text(varchar)" FROM VARCHAR_TBL;
+
+SELECT CAST(name 'namefield' AS text) AS "text(name)";
+
+SELECT CAST(f1 AS char) AS "char(text)" FROM TEXT_TBL;
+
+SELECT CAST(f1 AS char) AS "char(varchar)" FROM VARCHAR_TBL;
+
+SELECT CAST(name 'namefield' AS char) AS "char(name)";
+
+SELECT CAST(f1 AS varchar) AS "varchar(text)" FROM TEXT_TBL;
+
+SELECT CAST(f1 AS varchar) AS "varchar(char)" FROM CHAR_TBL;
+
+SELECT CAST(name 'namefield' AS varchar) AS "varchar(name)";
+
+--
+-- test SQL92 string functions
+--
+
+SELECT TRIM(BOTH FROM '  bunch o blanks  ') AS "bunch o blanks";
+
+SELECT TRIM(LEADING FROM '  bunch o blanks  ') AS "bunch o blanks  ";
+
+SELECT TRIM(TRAILING FROM '  bunch o blanks  ') AS "  bunch o blanks";
+
+SELECT TRIM(BOTH 'x' FROM 'xxxxxsome Xsxxxxx') AS "some Xs";
+
+SELECT SUBSTRING('1234567890' FROM 3) AS "34567890";
+
+SELECT SUBSTRING('1234567890' FROM 4 FOR 3) AS "456";
+
+SELECT POSITION('4' IN '1234567890') AS "4";
+
+SELECT POSITION(5 IN '1234567890') AS "5";
+
+--
+-- test implicit type conversion
+--
+
+SELECT 'unknown' || ' and unknown' AS "Concat unknown types";
+
+SELECT text 'text' || ' and unknown' AS "Concat text to unknown type";
+
+SELECT text 'text' || char ' and char' AS "Concat text to char";
+
+SELECT text 'text' || varchar ' and varchar' AS "Concat text to varchar";
 

src/test/regress/sql/tests

@@ -46,6 +46,7 @@ select_into
 select_distinct
 select_distinct_on
 subselect
+union
 aggregates
 transactions
 random

src/test/regress/sql/union.sql

+--
+-- union.sql
+--
+
+-- Simple UNION constructs
+
+SELECT 1 AS two UNION SELECT 2;
+
+SELECT 1 AS one UNION SELECT 1;
+
+SELECT 1 AS two UNION ALL SELECT 2;
+
+SELECT 1 AS two UNION ALL SELECT 1;
+
+SELECT 1 AS three UNION SELECT 2 UNION SELECT 3;
+
+SELECT 1 AS two UNION SELECT 2 UNION SELECT 2;
+
+SELECT 1 AS three UNION SELECT 2 UNION ALL SELECT 2;
+
+SELECT 1.1 AS two UNION SELECT 2.2;
+
+-- Mixed types
+
+SELECT 1.1 AS two UNION SELECT 2;
+
+SELECT 1 AS two UNION SELECT 2.2;
+
+SELECT 1 AS one UNION SELECT 1.1;
+
+SELECT 1.1 AS two UNION ALL SELECT 2;
+
+SELECT 1 AS two UNION ALL SELECT 1;
+
+SELECT 1 AS three UNION SELECT 2 UNION SELECT 3;
+
+SELECT 1 AS two UNION SELECT 2 UNION SELECT 2;
+
+SELECT 1 AS three UNION SELECT 2 UNION ALL SELECT 2;
+
+--
+-- Try testing from tables...
+--
+
+SELECT f1 AS five FROM FLOAT8_TBL
+UNION
+SELECT f1 FROM FLOAT8_TBL;
+
+SELECT f1 AS ten FROM FLOAT8_TBL
+UNION ALL
+SELECT f1 FROM FLOAT8_TBL;
+
+SELECT f1 AS nine FROM FLOAT8_TBL
+UNION
+SELECT f1 FROM INT4_TBL;
+
+SELECT f1 AS ten FROM FLOAT8_TBL
+UNION ALL
+SELECT f1 FROM INT4_TBL;
+
+SELECT f1 AS five FROM FLOAT8_TBL
+  WHERE f1 BETWEEN -1e6 AND 1e6
+UNION
+SELECT f1 FROM INT4_TBL
+  WHERE f1 BETWEEN 0 AND 1000000;
+
+SELECT f1 AS five FROM VARCHAR_TBL
+UNION
+SELECT f1 FROM CHAR_TBL;
+
+SELECT f1 AS three FROM VARCHAR_TBL
+UNION
+SELECT TRIM(TRAILING FROM f1) FROM CHAR_TBL;
+
+SELECT f1 AS eight FROM VARCHAR_TBL
+UNION ALL
+SELECT f1 FROM CHAR_TBL;
+
+SELECT f1 AS five FROM TEXT_TBL
+UNION
+SELECT f1 FROM VARCHAR_TBL
+UNION
+SELECT TRIM(TRAILING FROM f1) FROM CHAR_TBL;
+