Merge pull request #1277 from katzyn/misc

Assorted changes in Parser

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

@@ -28,7 +28,6 @@ import static org.h2.util.ParserUtil.INNER;
 import static org.h2.util.ParserUtil.INTERSECT;
 import static org.h2.util.ParserUtil.IS;
 import static org.h2.util.ParserUtil.JOIN;
-import static org.h2.util.ParserUtil.KEYWORD;
 import static org.h2.util.ParserUtil.LIKE;
 import static org.h2.util.ParserUtil.LIMIT;
 import static org.h2.util.ParserUtil.MINUS;
@@ -325,6 +324,66 @@ public class Parser {
      */
     private static final int DOT = COMMA + 1;
 
+    /**
+     * The token "{".
+     */
+    private static final int OPEN_BRACE = DOT + 1;
+
+    /**
+     * The token "}".
+     */
+    private static final int CLOSE_BRACE = OPEN_BRACE + 1;
+
+    /**
+     * The token "/".
+     */
+    private static final int SLASH = CLOSE_BRACE + 1;
+
+    /**
+     * The token "%".
+     */
+    private static final int PERCENT = SLASH + 1;
+
+    /**
+     * The token ";".
+     */
+    private static final int SEMICOLON = PERCENT + 1;
+
+    /**
+     * The token ":".
+     */
+    private static final int COLON = SEMICOLON + 1;
+
+    /**
+     * The token "[".
+     */
+    private static final int OPEN_BRACKET = COLON + 1;
+
+    /**
+     * The token "]".
+     */
+    private static final int CLOSE_BRACKET = OPEN_BRACKET + 1;
+
+    /**
+     * The token "~".
+     */
+    private static final int TILDE = CLOSE_BRACKET + 1;
+
+    /**
+     * The token "::".
+     */
+    private static final int COLON_COLON = TILDE + 1;
+
+    /**
+     * The token ":=".
+     */
+    private static final int COLON_EQ = COLON_COLON + 1;
+
+    /**
+     * The token "!~".
+     */
+    private static final int NOT_TILDE = COLON_EQ + 1;
+
     private static final String[] TOKENS = {
             // Unused
             null,
@@ -448,6 +507,30 @@ public class Parser {
             ",",
             // DOT
             ".",
+            // OPEN_BRACE
+            "{",
+            // CLOSE_BRACE
+            "}",
+            // SLASH
+            "/",
+            // PERCENT
+            "%",
+            // SEMICOLON
+            ";",
+            // COLON
+            ":",
+            // OPEN_BRACKET
+            "[",
+            // CLOSE_BRACKET
+            "]",
+            // TILDE
+            "~",
+            // COLON_COLON
+            "::",
+            // COLON_EQ
+            ":=",
+            // NOT_TILDE
+            "!~",
             // End
     };
 
@@ -527,7 +610,7 @@ public class Parser {
     public Command prepareCommand(String sql) {
         try {
             Prepared p = parse(sql);
-            boolean hasMore = isToken(";");
+            boolean hasMore = isToken(SEMICOLON);
             if (!hasMore && currentTokenType != END) {
                 throw getSyntaxError();
             }
@@ -589,13 +672,13 @@ public class Parser {
     private Prepared parsePrepared() {
         int start = lastParseIndex;
         Prepared c = null;
-        String token = currentToken;
-        if (token.length() == 0) {
+        switch (currentTokenType) {
+        case END:
+        case SEMICOLON:
             c = new NoOperation(session);
-        } else {
-            char first = token.charAt(0);
-            switch (first) {
-            case '?':
+            setSQL(c, null, start);
+            return c;
+        case PARAMETER:
             // read the ? as a parameter
             readTerm();
             // this is an 'out' parameter - set a dummy value
@@ -604,9 +687,20 @@ public class Parser {
             read("CALL");
             c = parseCall();
             break;
-            case '(':
+        case OPEN_PAREN:
+        case FROM:
+        case SELECT:
             c = parseSelect();
             break;
+        case WITH:
+            read();
+            c = parseWithStatementOrQuery();
+            break;
+        case IDENTIFIER:
+            if (currentTokenQuoted) {
+                break;
+            }
+            switch (currentToken.charAt(0)) {
             case 'a':
             case 'A':
                 if (readIf("ALTER")) {
@@ -658,12 +752,6 @@ public class Parser {
                     c = parseExecute();
                 }
                 break;
-            case 'f':
-            case 'F':
-                if (isToken(FROM)) {
-                    c = parseSelect();
-                }
-                break;
             case 'g':
             case 'G':
                 if (readIf("GRANT")) {
@@ -710,9 +798,7 @@ public class Parser {
                 break;
             case 's':
             case 'S':
-                if (isToken(SELECT)) {
-                    c = parseSelect();
-                } else if (readIf("SET")) {
+                if (readIf("SET")) {
                     c = parseSet();
                 } else if (readIf("SAVEPOINT")) {
                     c = parseSavepoint();
@@ -743,17 +829,9 @@ public class Parser {
                 if (readIf("VALUES")) {
                     c = parseValues();
                 }
-                break;
-            case 'w':
-            case 'W':
-                if (readIf(WITH)) {
-                    c = parseWithStatementOrQuery();
             }
-                break;
-            case ';':
-                c = new NoOperation(session);
-                break;
-            default:
+        }
+        if (c == null) {
             throw getSyntaxError();
         }
         if (indexedParameterList != null) {
@@ -765,7 +843,7 @@ public class Parser {
             }
             parameters = indexedParameterList;
         }
-            if (readIf("{")) {
+        if (readIf(OPEN_BRACE)) {
             do {
                 int index = (int) readLong() - 1;
                 if (index < 0 || index >= parameters.size()) {
@@ -775,21 +853,17 @@ public class Parser {
                 if (p == null) {
                     throw getSyntaxError();
                 }
-                    read(":");
+                read(COLON);
                 Expression expr = readExpression();
                 expr = expr.optimize(session);
                 p.setValue(expr.getValue(session));
             } while (readIf(COMMA));
-                read("}");
+            read(CLOSE_BRACE);
             for (Parameter p : parameters) {
                 p.checkSet();
             }
             parameters.clear();
         }
-        }
-        if (c == null) {
-            throw getSyntaxError();
-        }
         setSQL(c, null, start);
         return c;
     }
@@ -2797,7 +2871,7 @@ public class Parser {
         while (true) {
             if (readIf(STRING_CONCAT)) {
                 r = new Operation(OpType.CONCAT, r, readSum());
-            } else if (readIf("~")) {
+            } else if (readIf(TILDE)) {
                 if (readIf(ASTERISK)) {
                     Function function = Function.getFunction(database, "CAST");
                     function.setDataType(new Column("X",
@@ -2806,7 +2880,7 @@ public class Parser {
                     r = function;
                 }
                 r = new CompareLike(database, r, readSum(), null, true);
-            } else if (readIf("!~")) {
+            } else if (readIf(NOT_TILDE)) {
                 if (readIf(ASTERISK)) {
                     Function function = Function.getFunction(database, "CAST");
                     function.setDataType(new Column("X",
@@ -2840,9 +2914,9 @@ public class Parser {
         while (true) {
             if (readIf(ASTERISK)) {
                 r = new Operation(OpType.MULTIPLY, r, readTerm());
-            } else if (readIf("/")) {
+            } else if (readIf(SLASH)) {
                 r = new Operation(OpType.DIVIDE, r, readTerm());
-            } else if (readIf("%")) {
+            } else if (readIf(PERCENT)) {
                 r = new Operation(OpType.MODULUS, r, readTerm());
             } else {
                 return r;
@@ -3174,9 +3248,6 @@ public class Parser {
     }
 
     private Expression readFunctionWithoutParameters(String name) {
-        if (readIf(OPEN_PAREN)) {
-            read(CLOSE_PAREN);
-        }
         if (database.isAllowBuiltinAliasOverride()) {
             FunctionAlias functionAlias = database.getSchema(session.getCurrentSchemaName()).findFunction(name);
             if (functionAlias != null) {
@@ -3319,7 +3390,7 @@ public class Parser {
         case AT:
             read();
             r = new Variable(session, readAliasIdentifier());
-            if (readIf(":=")) {
+            if (readIf(COLON_EQ)) {
                 Expression value = readExpression();
                 Function function = Function.getFunction(database, "SET");
                 function.setParameter(0, r);
@@ -3377,16 +3448,8 @@ public class Parser {
                     r = readFunctionWithoutParameters("LOCALTIME");
                 } else if (equalsToken("SYSTIME", name)) {
                     r = readFunctionWithoutParameters("CURRENT_TIME");
-                } else if (equalsToken("CURRENT", name)) {
-                    if (readIf("TIMESTAMP")) {
-                        r = readFunctionWithoutParameters("CURRENT_TIMESTAMP");
-                    } else if (readIf("TIME")) {
-                        r = readFunctionWithoutParameters("CURRENT_TIME");
-                    } else if (readIf("DATE")) {
-                        r = readFunctionWithoutParameters("CURRENT_DATE");
-                    } else {
-                        r = new ExpressionColumn(database, null, null, name);
-                    }
+                } else if (database.getMode().getEnum() == ModeEnum.DB2 && equalsToken("CURRENT", name)) {
+                    r = parseDB2SpecialRegisters(name);
                 } else if (equalsToken("NEXT", name) && readIf("VALUE")) {
                     read(FOR);
                     Sequence sequence = readSequence();
@@ -3553,7 +3616,7 @@ public class Parser {
         default:
             throw getSyntaxError();
         }
-        if (readIf("[")) {
+        if (readIf(OPEN_BRACKET)) {
             Function function = Function.getFunction(database, "ARRAY_GET");
             function.setParameter(0, r);
             r = readExpression();
@@ -3561,9 +3624,9 @@ public class Parser {
                     .get(1)));
             function.setParameter(1, r);
             r = function;
-            read("]");
+            read(CLOSE_BRACKET);
         }
-        if (readIf("::")) {
+        if (readIf(COLON_COLON)) {
             // PostgreSQL compatibility
             if (isToken("PG_CATALOG")) {
                 read("PG_CATALOG");
@@ -3588,6 +3651,24 @@ public class Parser {
         return r;
     }
 
+    private Expression parseDB2SpecialRegisters(String name) {
+        // Only "CURRENT" name is supported
+        if (readIf("TIMESTAMP")) {
+            if (readIf(WITH)) {
+                read("TIME");
+                read("ZONE");
+                return readFunctionWithoutParameters("CURRENT_TIMESTAMP");
+            }
+            return readFunctionWithoutParameters("LOCALTIMESTAMP");
+        } else if (readIf("TIME")) {
+            return readFunctionWithoutParameters("CURRENT_TIME");
+        } else if (readIf("DATE")) {
+            return readFunctionWithoutParameters("CURRENT_DATE");
+        }
+        // No match, parse CURRENT as a column
+        return new ExpressionColumn(database, null, null, name);
+    }
+
     private Expression readCase() {
         if (readIf("END")) {
             readIf("CASE");
@@ -3912,16 +3993,13 @@ public class Parser {
         case CHAR_SPECIAL_2:
             if (types[i] == CHAR_SPECIAL_2) {
                 char c1 = chars[i++];
-                currentToken = sqlCommand.substring(start, i);
                 currentTokenType = getSpecialType2(c, c1);
             } else {
-                currentToken = sqlCommand.substring(start, i);
                 currentTokenType = getSpecialType1(c);
             }
             parseIndex = i;
             return;
         case CHAR_SPECIAL_1:
-            currentToken = sqlCommand.substring(start, i);
             currentTokenType = getSpecialType1(c);
             parseIndex = i;
             return;
@@ -4023,7 +4101,6 @@ public class Parser {
             return;
         }
         case CHAR_END:
-            currentToken = "";
             currentTokenType = END;
             parseIndex = i;
             return;
@@ -4368,15 +4445,23 @@ public class Parser {
         case ',':
             return COMMA;
         case '{':
+            return OPEN_BRACE;
         case '}':
+            return CLOSE_BRACE;
         case '/':
+            return SLASH;
         case '%':
+            return PERCENT;
         case ';':
+            return SEMICOLON;
         case ':':
+            return COLON;
         case '[':
+            return OPEN_BRACKET;
         case ']':
+            return CLOSE_BRACKET;
         case '~':
-            return KEYWORD;
+            return TILDE;
         case '(':
             return OPEN_PAREN;
         case ')':
@@ -4395,8 +4480,10 @@ public class Parser {
     private int getSpecialType2(char c0, char c1) {
         switch (c0) {
         case ':':
-            if (c1 == ':' || c1 == '=') {
-                return KEYWORD;
+            if (c1 == ':') {
+                return COLON_COLON;
+            } else if (c1 == '=') {
+                return COLON_EQ;
             }
             break;
         case '>':
@@ -4415,7 +4502,7 @@ public class Parser {
             if (c1 == '=') {
                 return NOT_EQUAL;
             } else if (c1 == '~') {
-                return KEYWORD;
+                return NOT_TILDE;
             }
             break;
         case '|':

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

@@ -561,6 +561,19 @@ public class TestCompatibility extends TestDb {
                 "select date from test where date = '2014-04-05-09.48.28.020005'");
         assertResult("2014-04-05 09:48:28.020005", stat,
                 "select date from test where date = '2014-04-05 09:48:28.020005'");
+
+        // Test limited support for DB2's special registers
+
+        // Standard SQL functions like LOCALTIMESTAMP, CURRENT_TIMESTAMP and
+        // others are used to compare values, their implementation in H2 is
+        // compatible with standard, but may be not really compatible with DB2.
+        assertResult("TRUE", stat, "SELECT LOCALTIMESTAMP = CURRENT TIMESTAMP");
+        assertResult("TRUE", stat, "SELECT CAST(LOCALTIMESTAMP AS VARCHAR) = CAST(CURRENT TIMESTAMP AS VARCHAR)");
+        assertResult("TRUE", stat, "SELECT CURRENT_TIMESTAMP = CURRENT TIMESTAMP WITH TIME ZONE");
+        assertResult("TRUE", stat,
+                "SELECT CAST(CURRENT_TIMESTAMP AS VARCHAR) = CAST(CURRENT TIMESTAMP WITH TIME ZONE AS VARCHAR)");
+        assertResult("TRUE", stat, "SELECT CURRENT_TIME = CURRENT TIME");
+        assertResult("TRUE", stat, "SELECT CURRENT_DATE = CURRENT DATE");
     }
 
     private void testDerby() throws SQLException {