Merge pull request #1096 from katzyn/parser

Parse and format TOP, INTERSECTS, and DUAL properly

h2/src/docsrc/html/advanced.html

@@ -503,9 +503,9 @@ unless they are quoted (surrounded with double quotes). The list is currently:
 </p><p>
 <code>
 ALL, CHECK, CONSTRAINT, CROSS, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, DISTINCT, EXCEPT,
-EXISTS, FALSE, FETCH, FOR, FOREIGN, FROM, FULL, GROUP, HAVING, INNER, INTERSECT, IS, JOIN,
-LIKE, LIMIT, MINUS, NATURAL, NOT, NULL, OFFSET, ON, ORDER, PRIMARY, ROWNUM, SELECT, SYSDATE,
-SYSTIME, SYSTIMESTAMP, TODAY, TRUE, UNION, UNIQUE, WHERE, WITH
+EXISTS, FALSE, FETCH, FOR, FOREIGN, FROM, FULL, GROUP, HAVING, INNER, INTERSECT, INTERSECTS,
+IS, JOIN, LIKE, LIMIT, MINUS, NATURAL, NOT, NULL, OFFSET, ON, ORDER, PRIMARY, ROWNUM, SELECT,
+SYSDATE, SYSTIME, SYSTIMESTAMP, TODAY, TOP, TRUE, UNION, UNIQUE, WHERE, WITH
 </code>
 </p><p>
 Certain words of this list are keywords because they are functions that can be used without '()' for compatibility,

h2/src/docsrc/html/changelog.html

@@ -21,8 +21,12 @@ Change Log
 
 <h2>Next Version (unreleased)</h2>
 <ul>
+<li>Issue #1089: Parser does not quote words INTERSECTS, DUAL, TOP
+</li>
 <li>Issue #230: Renaming a column does not update foreign key constraint 
 </li>
+<li>PR #1087: improve performance of planning large queries
+</li>
 <li>Issue #394: Recover tool places COLLATION and BINARY_COLLATION after temporary tables
 </li>
 <li>Improve the script-based unit testing to check the error code of the exception thrown. 

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

@@ -684,10 +684,6 @@ public class Parser {
             if (equalsToken("SESSION", schemaName)) {
                 // for local temporary tables
                 schema = database.getSchema(session.getCurrentSchemaName());
-            } else if (database.getMode().sysDummy1 &&
-                    "SYSIBM".equals(schemaName)) {
-                // IBM DB2 and Apache Derby compatibility: SYSIBM.SYSDUMMY1
-                schema = database.getSchema(session.getCurrentSchemaName());
             }
         }
         return schema;
@@ -1372,7 +1368,7 @@ public class Parser {
     private TableFilter readTableFilter() {
         Table table;
         String alias = null;
-        if (readIf("(")) {
+        label: if (readIf("(")) {
             if (isSelect()) {
                 Query query = parseSelectUnion();
                 read(")");
@@ -1406,7 +1402,19 @@ public class Parser {
             table = parseValuesTable(0).getTable();
         } else {
             String tableName = readIdentifierWithSchema(null);
-            Schema schema = getSchema();
+            Schema schema;
+            if (schemaName == null) {
+                schema = null;
+            } else {
+                schema = findSchema(schemaName);
+                if (schema == null) {
+                    if (isDualTable(tableName)) {
+                        table = getDualTable(false);
+                        break label;
+                    }
+                    throw DbException.get(ErrorCode.SCHEMA_NOT_FOUND_1, schemaName);
+                }
+            }
             boolean foundLeftBracket = readIf("(");
             if (foundLeftBracket && readIf("INDEX")) {
                 // Sybase compatibility with
@@ -1442,13 +1450,8 @@ public class Parser {
                     }
                     table = new FunctionTable(mainSchema, session, expr, call);
                 }
-            } else if (equalsToken("DUAL", tableName)) {
-                table = getDualTable(false);
-            } else if (database.getMode().sysDummy1 &&
-                    equalsToken("SYSDUMMY1", tableName)) {
-                table = getDualTable(false);
             } else {
-                table = readTableOrView(tableName);
+                table = readTableOrView(tableName, true);
             }
         }
         ArrayList<String> derivedColumnNames = null;
@@ -4206,7 +4209,7 @@ public class Parser {
             // if not yet converted to uppercase, do it now
             s = StringUtils.toUpperEnglish(s);
         }
-        return getSaveTokenType(s, false);
+        return ParserUtil.getSaveTokenType(s, false);
     }
 
     private boolean isKeyword(String s) {
@@ -4217,10 +4220,6 @@ public class Parser {
         return ParserUtil.isKeyword(s);
     }
 
-    private static int getSaveTokenType(String s, boolean functionsAsKeywords) {
-        return ParserUtil.getSaveTokenType(s, functionsAsKeywords);
-    }
-
     private Column parseColumnForTable(String columnName,
             boolean defaultNullable) {
         Column column;
@@ -5937,15 +5936,23 @@ public class Parser {
         return command;
     }
 
+    boolean isDualTable(String tableName) {
+        return ((schemaName == null || equalsToken(schemaName, "SYS")) && equalsToken("DUAL", tableName))
+                || (database.getMode().sysDummy1 && (schemaName == null || equalsToken(schemaName, "SYSIBM")))
+                        && equalsToken("SYSDUMMY1", tableName);
+    }
+
     private Table readTableOrView() {
-        return readTableOrView(readIdentifierWithSchema(null));
+        return readTableOrView(readIdentifierWithSchema(null), false);
     }
 
-    private Table readTableOrView(String tableName) {
-        // same algorithm than readSequence
+    private Table readTableOrView(String tableName, boolean allowDual) {
         if (schemaName != null) {
-            return getSchema().getTableOrView(session, tableName);
+            Table table = getSchema().resolveTableOrView(session, tableName);
+            if (table != null) {
+                return table;
             }
+        } else {
             Table table = database.getSchema(session.getCurrentSchemaName())
                     .resolveTableOrView(session, tableName);
             if (table != null) {
@@ -5961,6 +5968,10 @@ public class Parser {
                     }
                 }
             }
+        }
+        if (allowDual && isDualTable(tableName)) {
+            return getDualTable(false);
+        }
         throw DbException.get(ErrorCode.TABLE_OR_VIEW_NOT_FOUND_1, tableName);
     }
 
@@ -6878,7 +6889,7 @@ public class Parser {
         if (s == null) {
             return "\"\"";
         }
-        if (ParserUtil.isSimpleIdentifier(s, false)) {
+        if (ParserUtil.isSimpleIdentifier(s)) {
             return s;
         }
         return StringUtils.quoteIdentifier(s);

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

@@ -1405,7 +1405,7 @@ public class JdbcStatement extends TraceObject implements Statement, JdbcStateme
      */
     @Override
     public boolean isSimpleIdentifier(String identifier) throws SQLException {
-        return ParserUtil.isSimpleIdentifier(identifier, true);
+        return ParserUtil.isSimpleIdentifier(identifier);
     }
 
     /**

h2/src/main/org/h2/util/ParserUtil.java

@@ -58,11 +58,10 @@ public class ParserUtil {
      * Is this a simple identifier (in the JDBC specification sense).
      *
      * @param s identifier to check
-     * @param functionsAsKeywords treat system functions as keywords
      * @return is specified identifier may be used without quotes
      * @throws NullPointerException if s is {@code null}
      */
-    public static boolean isSimpleIdentifier(String s, boolean functionsAsKeywords) {
+    public static boolean isSimpleIdentifier(String s) {
         if (s.length() == 0) {
             return false;
         }
@@ -78,17 +77,18 @@ public class ParserUtil {
                 return false;
             }
         }
-        return getSaveTokenType(s, functionsAsKeywords) == IDENTIFIER;
+        return getSaveTokenType(s, true) == IDENTIFIER;
     }
 
     /**
      * Get the token type.
      *
      * @param s the token
-     * @param functionsAsKeywords whether "current data / time" functions are keywords
+     * @param additionalKeywords whether TOP, INTERSECTS, and "current data /
+     *                           time" functions are keywords
      * @return the token type
      */
-    public static int getSaveTokenType(String s, boolean functionsAsKeywords) {
+    public static int getSaveTokenType(String s, boolean additionalKeywords) {
         switch (s.charAt(0)) {
         case 'A':
             return getKeywordOrIdentifier(s, "ALL", KEYWORD);
@@ -100,7 +100,7 @@ public class ParserUtil {
             } else if ("CROSS".equals(s)) {
                 return KEYWORD;
             }
-            if (functionsAsKeywords) {
+            if (additionalKeywords) {
                 if ("CURRENT_DATE".equals(s) || "CURRENT_TIME".equals(s) || "CURRENT_TIMESTAMP".equals(s)) {
                     return KEYWORD;
                 }
@@ -131,12 +131,15 @@ public class ParserUtil {
         case 'H':
             return getKeywordOrIdentifier(s, "HAVING", KEYWORD);
         case 'I':
-            if ("INNER".equals(s)) {
+            if ("INNER".equals(s) || "INTERSECT".equals(s) || "IS".equals(s)) {
                 return KEYWORD;
-            } else if ("INTERSECT".equals(s)) {
+            }
+            if (additionalKeywords) {
+                if ("INTERSECTS".equals(s)) {
                     return KEYWORD;
                 }
-            return getKeywordOrIdentifier(s, "IS", KEYWORD);
+            }
+            return IDENTIFIER;
         case 'J':
             return getKeywordOrIdentifier(s, "JOIN", KEYWORD);
         case 'L':
@@ -168,7 +171,7 @@ public class ParserUtil {
             if ("SELECT".equals(s)) {
                 return KEYWORD;
             }
-            if (functionsAsKeywords) {
+            if (additionalKeywords) {
                 if ("SYSDATE".equals(s) || "SYSTIME".equals(s) || "SYSTIMESTAMP".equals(s)) {
                     return KEYWORD;
                 }
@@ -178,8 +181,8 @@ public class ParserUtil {
             if ("TRUE".equals(s)) {
                 return TRUE;
             }
-            if (functionsAsKeywords) {
-                if ("TODAY".equals(s)) {
+            if (additionalKeywords) {
+                if ("TODAY".equals(s) || "TOP".equals(s)) {
                     return KEYWORD;
                 }
             }

h2/src/test/org/h2/test/scripts/TestScript.java

@@ -87,6 +87,7 @@ public class TestScript extends TestBase {
 
         testScript("testScript.sql");
         testScript("derived-column-names.sql");
+        testScript("dual.sql");
         testScript("indexes.sql");
         testScript("information_schema.sql");
         testScript("joins.sql");

h2/src/test/org/h2/test/scripts/dual.sql

+-- Copyright 2004-2018 H2 Group. Multiple-Licensed under the MPL 2.0,
+-- and the EPL 1.0 (http://h2database.com/html/license.html).
+-- Initial Developer: H2 Group
+--
+
+SELECT * FROM DUAL;
+>> 1
+
+CREATE TABLE DUAL(A INT);
+> ok
+
+INSERT INTO DUAL VALUES (2);
+> update count: 1
+
+SELECT A FROM DUAL;
+>> 2
+
+SELECT * FROM SYS.DUAL;
+>> 1
+
+DROP TABLE DUAL;
+> ok
+
+SET MODE DB2;
+> ok
+
+SELECT * FROM SYSDUMMY1;
+>> 1
+
+CREATE TABLE SYSDUMMY1(A INT);
+> ok
+
+INSERT INTO SYSDUMMY1 VALUES (2);
+> update count: 1
+
+SELECT A FROM SYSDUMMY1;
+>> 2
+
+SELECT * FROM SYSIBM.SYSDUMMY1;
+>> 1
+
+DROP TABLE SYSDUMMY1;
+> ok
+
+SET MODE Regular;
+> ok