Implement ILIKE operator for case-insensitive matching

h2/src/docsrc/help/help.csv

@@ -1809,7 +1809,7 @@ compare { { { ALL | ANY | SOME } ( select ) } | operand }
     | IS [ NOT ] [ DISTINCT FROM ] operand
     | BETWEEN operand AND operand
     | IN ( { select | expression [,...] } )
-    | [ NOT ] LIKE operand [ ESCAPE string ]
+    | [ NOT ] [ LIKE | ILIKE ] operand [ ESCAPE string ]
     | [ NOT ] REGEXP operand
 ","
 The right hand side of a condition.
@@ -1826,6 +1826,8 @@ At most one escape character is allowed.
 Each character that follows the escape character in the pattern needs to match exactly.
 Patterns that end with an escape character are invalid and the expression returns NULL.
 
+ILIKE does a case-insensitive compare.
+
 When comparing with REGEXP, regular expression matching is used.
 See Java ""Matcher.find"" for details.
 ","

h2/src/docsrc/html/changelog.html

@@ -21,6 +21,8 @@ Change Log
 
 <h2>Next Version (unreleased)</h2>
 <ul>
+<li>Implement ILIKE operator for case-insensitive matching
+</li>
 <li>Optimise LIKE queries for the common cases of '%Foo' and '%Foo%'
 </li>
 <li>Issue #387: H2 MSSQL Compatibility Mode - Support uniqueidentifier

h2/src/main/org/h2/command/Parser.java

@@ -2148,6 +2148,18 @@ public class Parser {
                 }
                 recompileAlways = true;
                 r = new CompareLike(database, r, b, esc, false);
+            } else if (readIf("ILIKE")) {
+                Function function = Function.getFunction(database, "CAST");
+                function.setDataType(new Column("X", Value.STRING_IGNORECASE));
+                function.setParameter(0, r);
+                r = function;
+                Expression b = readConcat();
+                Expression esc = null;
+                if (readIf("ESCAPE")) {
+                    esc = readConcat();
+                }
+                recompileAlways = true;
+                r = new CompareLike(database, r, b, esc, false);
             } else if (readIf("REGEXP")) {
                 Expression b = readConcat();
                 r = new CompareLike(database, r, b, null, true);

h2/src/test/org/h2/test/testScript.sql

@@ -7378,6 +7378,17 @@ SELECT * FROM TEST WHERE NAME LIKE 'Hello%';
 > 1  Hello
 > rows: 1
 
+SELECT * FROM TEST WHERE NAME ILIKE 'hello%';
+> ID NAME
+> -- -----
+> 1  Hello
+> rows: 1
+
+SELECT * FROM TEST WHERE NAME ILIKE 'xxx%';
+> ID NAME
+> -- ----
+> rows: 0
+
 SELECT * FROM TEST WHERE NAME LIKE 'Wo%';
 > ID NAME
 > -- -----