Improved MySQL compatibility by supporting "use schema". Thanks a lot to Karl…

Improved MySQL compatibility by supporting "use schema". Thanks a lot to Karl Pietrzak for the patch!

h2/src/docsrc/html/changelog.html

@@ -17,7 +17,9 @@ Change Log
 <h1>Change Log</h1>
 
 <h2>Next Version (unreleased)</h2>
-<ul><li>Writing to the trace file is now faster, specially with the debug level.
+<ul><li>Improved MySQL compatibility by supporting "use schema".
+    Thanks a lot to Karl Pietrzak for the patch!
+</li><li>Writing to the trace file is now faster, specially with the debug level.
 </li><li>The database option "defrag_always=true" did not work with the MVStore.
 </li><li>The JDBC escape syntax {ts 'value'} did not interpret the value as a timestamp.
     The same for {d 'value'} (for date) and {t 'value'} (for time).

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

@@ -453,6 +453,8 @@ public class Parser {
             case 'U':
                 if (readIf("UPDATE")) {
                     c = parseUpdate();
+                } else if (readIf("USE")) {
+                    c = parseUse();
                 }
                 break;
             case 'v':
@@ -5065,6 +5067,16 @@ public class Parser {
         }
     }
 
+    private Prepared parseUse() {
+        if (readIf("SCHEMA")) {
+            readIfEqualOrTo();
+            Set command = new Set(session, SetTypes.SCHEMA);
+            command.setString(readAliasIdentifier());
+            return command;
+        }
+        throw getSyntaxError();
+    }
+
     private Set parseSetCollation() {
         Set command = new Set(session, SetTypes.COLLATION);
         String name = readAliasIdentifier();

h2/src/test/org/h2/test/db/TestCompatibility.java

@@ -230,6 +230,14 @@ public class TestCompatibility extends TestBase {
 
     private void testMySQL() throws SQLException {
         Statement stat = conn.createStatement();
+        stat.execute("create schema test_schema");
+        stat.execute("use schema test_schema");
+        assertResult("TEST_SCHEMA", stat,
+                "select schema()");
+        stat.execute("use schema public");
+        assertResult("PUBLIC", stat,
+                "select schema()");
+        
         stat.execute("SELECT 1");
         stat.execute("DROP TABLE IF EXISTS TEST");
         stat.execute("CREATE TABLE TEST(ID INT PRIMARY KEY, NAME VARCHAR)");