Implement enquoteIdentifier() and isSimpleIdentifier() from JDBC 4.3

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

@@ -6851,6 +6851,30 @@ public class Parser {
         return s;
     }
 
+    /**
+     * @param s
+     *            identifier to check
+     * @return is specified identifier may be used without quotes
+     */
+    public static boolean isSimpleIdentifier(String s) {
+        if (s == null || s.length() == 0) {
+            return false;
+        }
+        char c = s.charAt(0);
+        // lowercase a-z is quoted as well
+        if ((!Character.isLetter(c) && c != '_') || Character.isLowerCase(c)) {
+            return false;
+        }
+        for (int i = 1, length = s.length(); i < length; i++) {
+            c = s.charAt(i);
+            if ((!Character.isLetterOrDigit(c) && c != '_') ||
+                    Character.isLowerCase(c)) {
+                return false;
+            }
+        }
+        return !isKeyword(s, true);
+    }
+
     public void setLiteralsChecked(boolean literalsChecked) {
         this.literalsChecked = literalsChecked;
     }

h2/src/main/org/h2/jdbc/JdbcStatement.java

@@ -11,14 +11,17 @@ import java.sql.SQLException;
 import java.sql.SQLWarning;
 import java.sql.Statement;
 import java.util.ArrayList;
+
 import org.h2.api.ErrorCode;
 import org.h2.command.CommandInterface;
+import org.h2.command.Parser;
 import org.h2.engine.SessionInterface;
 import org.h2.engine.SysProperties;
 import org.h2.message.DbException;
 import org.h2.message.TraceObject;
 import org.h2.result.ResultInterface;
 import org.h2.util.New;
+import org.h2.util.StringUtils;
 
 /**
  * Represents a statement.
@@ -1295,6 +1298,33 @@ public class JdbcStatement extends TraceObject implements Statement, JdbcStateme
         }
     }
 
+    /**
+     * @param identifier
+     *            identifier to quote if required
+     * @param alwaysQuote
+     *            if {@code true} identifier will be quoted unconditionally
+     * @return specified identifier quoted if required or explicitly requested
+     */
+    @Override
+    public String enquoteIdentifier(String identifier, boolean alwaysQuote) throws SQLException {
+        if (alwaysQuote)
+            return StringUtils.quoteIdentifier(identifier);
+        return Parser.quoteIdentifier(identifier);
+    }
+
+    /**
+     * @param identifier
+     *            identifier to check
+     * @return is specified identifier may be used without quotes
+     */
+    @Override
+    public boolean isSimpleIdentifier(String identifier) throws SQLException {
+        if (identifier == null)
+            // To conform with JDBC specification
+            throw new NullPointerException();
+        return Parser.isSimpleIdentifier(identifier);
+    }
+
     /**
      * INTERNAL
      */

h2/src/main/org/h2/jdbc/JdbcStatementBackwardsCompat.java

@@ -32,4 +32,10 @@ public interface JdbcStatementBackwardsCompat {
     long executeLargeUpdate(String sql, int columnIndexes[]) throws SQLException;
 
     long executeLargeUpdate(String sql, String columnNames[]) throws SQLException;
+
+    // JDBC 4.3 (incomplete)
+
+    String enquoteIdentifier(String identifier, boolean alwaysQuote) throws SQLException;
+
+    boolean isSimpleIdentifier(String identifier) throws SQLException;
 }

h2/src/test/org/h2/test/jdbc/TestStatement.java

@@ -330,6 +330,17 @@ public class TestStatement extends TestBase {
         assertTrue(stat.getWarnings() == null);
         assertTrue(conn == stat.getConnection());
 
+        assertEquals("SOME_ID", statBC.enquoteIdentifier("SOME_ID", false));
+        assertEquals("\"SOME ID\"", statBC.enquoteIdentifier("SOME ID", false));
+        assertEquals("\"SOME_ID\"", statBC.enquoteIdentifier("SOME_ID", true));
+        assertEquals("\"FROM\"", statBC.enquoteIdentifier("FROM", false));
+        assertEquals("\"Test\"", statBC.enquoteIdentifier("Test", false));
+
+        assertTrue(statBC.isSimpleIdentifier("SOME_ID"));
+        assertFalse(statBC.isSimpleIdentifier("SOME ID"));
+        assertFalse(statBC.isSimpleIdentifier("FROM"));
+        assertFalse(statBC.isSimpleIdentifier("Test"));
+
         stat.close();
     }