Merge pull request #522 from stumc/Issue#479

Issue#479 Allow non-recursive CTEs (WITH statements)

h2/src/docsrc/help/help.csv

@@ -193,12 +193,16 @@ SHOW TABLES
 "
 
 "Commands (DML)","WITH","
-WITH [ RECURSIVE ] name ( columnName [,...] )
-    AS ( select )
+WITH [ RECURSIVE ] { name [( columnName [,...] )]
+    AS ( select ) [,...] }
     select
 ","
-Can be used to create a recursive query. The first select has to be a UNION.
-Currently only one result set can be referred to by name.
+Can be used to create a recursive query. 
+For recursive queries the first select has to be a UNION.
+Non-recursive queries are also supported.
+One or more common table entries can be use referred to by name..
+Column name declarations are now optional - the column names will be inferred from the named select queries.
+Positional parameters are not currently supported.
 ","
 WITH RECURSIVE t(n) AS (
         SELECT 1
@@ -208,6 +212,14 @@ WITH RECURSIVE t(n) AS (
         WHERE n < 100
 )
 SELECT sum(n) FROM t;
+","
+WITH t1 AS (
+        SELECT 1 AS FIRST_COLUMN
+),
+     t2 AS (
+        SELECT FIRST_COLUMN+1 AS FIRST_COLUMN FROM t1
+)
+SELECT sum(FIRST_COLUMN) FROM t2;
 "
 
 "Commands (DDL)","ALTER INDEX RENAME","

h2/src/docsrc/html/changelog.html

@@ -31,6 +31,8 @@ Change Log
 </li>
 <li>Issue #472: Support CREATE SEQUENCE ... ORDER as a NOOP for Oracle compatibility
 </li>
+<li>Issue #479: Allow non-recursive Common Table Expressions (CTE)
+</li>
 </ul>
 
 <h2>Version 1.4.195 (2017-04-23)</h2>

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

@@ -17,6 +17,8 @@ import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashSet;
 import java.util.LinkedHashSet;
+import java.util.List;
+
 import org.h2.api.ErrorCode;
 import org.h2.api.Trigger;
 import org.h2.command.ddl.AlterIndexRename;
@@ -4855,16 +4857,33 @@ public class Parser {
     }
 
     private Query parseWith() {
+    	List<TableView> viewsCreated = new ArrayList<TableView>();
         readIf("RECURSIVE");        
+        do{
+        	viewsCreated.add(parseSingleCommonTableExpression());
+        } while(readIf(","));
+        
+        Query q = parseSelectUnion();
+        q.setPrepareAlways(true);
+        return q;
+    }
+
+	private TableView parseSingleCommonTableExpression() {
 		String tempViewName = readIdentifierWithSchema();
 		Schema schema = getSchema();
 		Table recursiveTable;
-        read("(");
 		ArrayList<Column> columns = New.arrayList();
-        String[] cols = parseColumnList();
+		String[] cols = null;
+		
+		// column names are now optional - they can be inferred from the named
+		// query if not supplied
+		if(readIf("(")){
+		    cols = parseColumnList();
 		    for (String c : cols) {
+		    	// we dont really know the type of the column, so string will have to do
 		        columns.add(new Column(c, Value.STRING));
 		    }
+		}
 		Table old = session.findLocalTempTable(tempViewName);
 		if (old != null) {
 		    if (!(old instanceof TableView)) {
@@ -4878,6 +4897,9 @@ public class Parser {
 		    }
 		    session.removeLocalTempTable(old);
 		}
+		// this table is created as a work around because recursive 
+		// table expressions need to reference something that look like themselves
+		// to work (its removed after creation in this method)
 		CreateTableData data = new CreateTableData();
 		data.id = database.allocateObjectId();
 		data.columns = columns;
@@ -4890,7 +4912,7 @@ public class Parser {
 		recursiveTable = schema.createTable(data);
 		session.addLocalTempTable(recursiveTable);
 		String querySQL;
-        Column[] columnTemplates = new Column[cols.length];
+		List<Column> columnTemplateList = new ArrayList<Column>();
 		try {
 		    read("AS");
 		    read("(");
@@ -4899,22 +4921,32 @@ public class Parser {
 		    withQuery.prepare();
 		    querySQL = StringUtils.cache(withQuery.getPlanSQL());
 		    ArrayList<Expression> withExpressions = withQuery.getExpressions();
-            for (int i = 0; i < cols.length; ++i) {
-                columnTemplates[i] = new Column(cols[i], withExpressions.get(i).getType());
+		    for (int i = 0; i < withExpressions.size(); ++i) {
+		    	String columnName = cols != null ? cols[i] : withExpressions.get(i).getColumnName();
+		    	columnTemplateList.add(new Column(columnName, withExpressions.get(i).getType()));
 		    }
 		} finally {
 		    session.removeLocalTempTable(recursiveTable);
 		}
 		int id = database.allocateObjectId();
-        TableView view = new TableView(schema, id, tempViewName, querySQL,
-                parameters, columnTemplates, session, true);
+		boolean isRecursive = true;
+		TableView view = null;
+		do{
+			view = new TableView(schema, id, tempViewName, querySQL,
+		        parameters, columnTemplateList.toArray(new Column[0]), session, 
+		        isRecursive);
+			if(view.isRecursiveQueryDetected()!=isRecursive){
+				isRecursive = view.isRecursiveQueryDetected();
+				view = null;
+				continue;
+			}
+		
+		} while(view==null);
 		view.setTableExpression(true);
 		view.setTemporary(true);
 		session.addLocalTempTable(view);
 		view.setOnCommitDrop(true);
-        Query q = parseSelectUnion();
-        q.setPrepareAlways(true);
-        return q;
+		return view;
 	}
 
     private CreateView parseCreateView(boolean force, boolean orReplace) {

h2/src/main/org/h2/res/help.csv

@@ -67,8 +67,8 @@ SHOW { SCHEMAS | TABLES [ FROM schemaName ] |
 ","
 Lists the schemas, tables, or the columns of a table."
 "Commands (DML)","WITH","
-WITH [ RECURSIVE ] name ( columnName [,...] )
-    AS ( select )
+WITH [ RECURSIVE ] { name [( columnName [,...] )]
+    AS ( select ) [,...] }
     select
 ","
 Can be used to create a recursive query."

h2/src/main/org/h2/table/RangeTable.java

@@ -144,7 +144,7 @@ public class RangeTable extends Table {
 
     @Override
     public TableType getTableType() {
-        throw DbException.throwInternalError(toString());
+    	return TableType.SYSTEM_TABLE;
     }
 
     @Override

h2/src/main/org/h2/table/TableView.java

@@ -57,6 +57,7 @@ public class TableView extends Table {
     private Query topQuery;
     private ResultInterface recursiveResult;
     private boolean tableExpression;
+	private boolean isRecursiveQueryDetected;
 
     public TableView(Schema schema, int id, String name, String querySQL,
             ArrayList<Parameter> params, Column[] columnTemplates, Session session,
@@ -94,6 +95,7 @@ public class TableView extends Table {
         this.querySQL = querySQL;
         this.columnTemplates = columnTemplates;
         this.recursive = recursive;
+        this.isRecursiveQueryDetected = false;
         index = new ViewIndex(this, querySQL, params, recursive);
         initColumnsAndTables(session);
     }
@@ -206,6 +208,11 @@ public class TableView extends Table {
             // if it can't be compiled, then it's a 'zero column table'
             // this avoids problems when creating the view when opening the
             // database
+            
+            // if it can not be compiled - it could also be a recursive common table expression query
+            if(isRecursiveQueryExceptionDetected(createException)){
+            	this.isRecursiveQueryDetected = true;
+            }
             tables = New.arrayList();
             cols = new Column[0];
             if (recursive && columnTemplates != null) {
@@ -666,4 +673,29 @@ public class TableView extends Table {
         }
     }
     
+    /**
+     * If query recursion is detected (for recursion detection)
+     * @return is Recursive Query Flag Set
+     */
+    public boolean isRecursiveQueryDetected(){
+    	return isRecursiveQueryDetected;
+    }
+    
+    /**
+     * If query an exception indicates query recursion
+     * @return is Recursive Query Exception Detected
+     */    
+    private boolean isRecursiveQueryExceptionDetected(DbException exception){
+    	if (exception==null){
+    		return false;
+    	}
+    	if (exception.getErrorCode()!=ErrorCode.TABLE_OR_VIEW_NOT_FOUND_1){
+    		return false;
+    	}
+    	if (! exception.getMessage().contains("\""+this.getName()+"\"")){
+    		return false;
+    	}
+    	return true;
+    }
+
 }

h2/src/test/org/h2/test/TestAll.java

@@ -11,6 +11,7 @@ import java.util.ArrayList;
 import java.util.Properties;
 import java.util.TimerTask;
 import java.util.concurrent.TimeUnit;
+
 import org.h2.Driver;
 import org.h2.engine.Constants;
 import org.h2.store.fs.FilePathRec;
@@ -37,6 +38,7 @@ import org.h2.test.db.TestExclusive;
 import org.h2.test.db.TestFullText;
 import org.h2.test.db.TestFunctionOverload;
 import org.h2.test.db.TestFunctions;
+import org.h2.test.db.TestGeneralCommonTableQueries;
 import org.h2.test.db.TestIndex;
 import org.h2.test.db.TestIndexHints;
 import org.h2.test.db.TestLargeBlob;
@@ -738,6 +740,7 @@ kill -9 `jps -l | grep "org.h2.test." | cut -d " " -f 1`
         addTest(new TestOutOfMemory());
         addTest(new TestReadOnly());
         addTest(new TestRecursiveQueries());
+        addTest(new TestGeneralCommonTableQueries());
         addTest(new TestRights());
         addTest(new TestRunscript());
         addTest(new TestSQLInjection());

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

+/*
+ * Copyright 2004-2014 H2 Group. Multiple-Licensed under the MPL 2.0,
+ * and the EPL 1.0 (http://h2database.com/html/license.html).
+ * Initial Developer: H2 Group
+ */
+package org.h2.test.db;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.Statement;
+import org.h2.test.TestBase;
+
+/**
+ * Test non-recursive queries using WITH, but more than one common table defined.
+ */
+public class TestGeneralCommonTableQueries extends TestBase {
+
+	/**
+     * Run just this test.
+     *
+     * @param a ignored
+     */
+    public static void main(String... a) throws Exception {
+        TestBase.createCaller().init().test();
+    }
+
+    @Override
+    public void test() throws Exception {
+        testSimple();
+        testImpliedColumnNames();
+        testChainedQuery();
+    }
+
+    private void testSimple() throws Exception {
+        deleteDb("commonTableExpressionQueries");
+        Connection conn = getConnection("commonTableExpressionQueries");
+        Statement stat;
+        PreparedStatement prep;
+        ResultSet rs;
+
+        stat = conn.createStatement();
+        final String simple_two_column_query = "with " +
+            "t1(n) as (select 1 as first) " +
+            ",t2(n) as (select 2 as first) " +
+            "select * from t1 union all select * from t2";        
+        rs = stat.executeQuery(simple_two_column_query);
+        assertTrue(rs.next());
+        assertEquals(1, rs.getInt(1));
+        assertTrue(rs.next());
+        assertEquals(2, rs.getInt(1));
+        assertFalse(rs.next());
+        
+        prep = conn.prepareStatement(simple_two_column_query);
+        rs = prep.executeQuery();
+        assertTrue(rs.next());
+        assertEquals(1, rs.getInt(1));
+        assertTrue(rs.next());
+        assertEquals(2, rs.getInt(1));
+        assertFalse(rs.next());
+        
+        prep = conn.prepareStatement("with " +
+            "t1(n) as (select 2 as first) " +
+            ",t2(n) as (select 3 as first) " +
+            "select * from t1 union all select * from t2 where n<>?");
+        prep.setInt(1, 0); // omit no lines since zero is not in list
+        rs = prep.executeQuery();
+        assertTrue(rs.next());
+        assertEquals(2, rs.getInt(1));
+        assertTrue(rs.next());
+        assertEquals(3, rs.getInt(1));
+        assertFalse(rs.next());
+        
+        prep = conn.prepareStatement("with " +
+            "t1(n) as (select 2 as first) " +
+            ",t2(n) as (select 3 as first) " +
+            ",t3(n) as (select 4 as first) " +
+            "select * from t1 union all select * from t2 union all select * from t3 where n<>?");
+        prep.setInt(1, 4); // omit 4 line (last)
+        rs = prep.executeQuery();
+        assertTrue(rs.next());
+        assertEquals(2, rs.getInt(1));
+        assertTrue(rs.next());
+        assertEquals(3, rs.getInt(1));
+        assertFalse(rs.next());
+                
+        conn.close();
+        deleteDb("commonTableExpressionQueries");
+    }
+
+    private void testImpliedColumnNames() throws Exception {
+        deleteDb("commonTableExpressionQueries");
+        Connection conn = getConnection("commonTableExpressionQueries");
+        PreparedStatement prep;
+        ResultSet rs;
+      
+        prep = conn.prepareStatement("with " +
+            "t1 as (select 2 as first_col) " +
+            ",t2 as (select first_col+1 from t1) " +
+            ",t3 as (select 4 as first_col) " +
+            "select * from t1 union all select * from t2 union all select * from t3 where first_col<>?");
+        prep.setInt(1, 4); // omit 4 line (last)
+        rs = prep.executeQuery();
+        assertTrue(rs.next());
+        assertEquals(2, rs.getInt(1));
+        assertTrue(rs.next());
+        assertEquals(3, rs.getInt("FIRST_COL"));
+        assertFalse(rs.next());
+        assertEquals(rs.getMetaData().getColumnCount(),1);
+        assertEquals("FIRST_COL",rs.getMetaData().getColumnLabel(1));
+        
+        conn.close();
+        deleteDb("commonTableExpressionQueries");
+    }
+        
+    private void testChainedQuery() throws Exception {
+        deleteDb("commonTableExpressionQueries");
+        Connection conn = getConnection("commonTableExpressionQueries");
+        PreparedStatement prep;
+        ResultSet rs;
+      
+        prep = conn.prepareStatement("    WITH t1 AS ("
+    	    +"        SELECT 1 AS FIRST_COLUMN"
+    	    +"),"
+    	    +"     t2 AS ("
+    	    +"        SELECT FIRST_COLUMN+1 AS FIRST_COLUMN FROM t1 "
+    	    +") "
+    	    +"SELECT sum(FIRST_COLUMN) FROM t2");
+        rs = prep.executeQuery();
+        assertTrue(rs.next());
+        assertEquals(2, rs.getInt(1));
+        assertFalse(rs.next());
+        
+        conn.close();
+        deleteDb("commonTableExpressionQueries");
+    }    
+}

h2/src/tools/org/h2/build/doc/dictionary.txt

@@ -12,7 +12,7 @@ adapting adaptive add added addiction adding addition additional additionally
 additions addon addr address addressed addresses adds adeptia adjacent adjust
 adjusted adjusts admin administration administrator admins admission ado adopt
 advanced advances advantage advantages advised aeiou aejaks aelig aes afaik
-affect affected affects affero affine after afterwards again against agar age
+affect affected affects affero affine affinity after afterwards again against agar age
 agent agentlib agg aggregate aggregated aggregates aggregating aggressive agile
 agrave agree agreeable agreed agreement agreements agrees ahead
 ahilmnqbjkcdeopfrsg aid ajax alan alarm ale alefsym alert alessio alexander alfki
@@ -300,7 +300,7 @@ icmpgt icmple icmplt icmpne ico icon iconified icons iconst icu ide idea ideal
 ideas identical identification identified identifier identifiers identify identifying
 identities identity idiomatic idiv idle ids idx idxname iee ieee iexcl iface ifeq
 ifexists ifge ifgt ifle iflt ifne ifnonnull ifnull iframe ifx ignore ignorecase ignored
-ignoredriverprivileges ignorelist ignores ignoring igrave iinc ikura ikvm ikvmc
+ignoredriverprivileges ignorelist ignores ignoring ignite igrave iinc ikura ikvm ikvmc
 illegal iload image imageio images imaginary img iml immediately immutable imola imp
 impact imperial impersonate impl imple implement implementation implementations
 implemented implementing implements implication implicit implicitly implied
@@ -315,7 +315,7 @@ indemnified indemnify indemnity indent indentation indentations indented indents
 independent independently index indexdef indexed indexer indexers indexes indexid
 indexing indicate indicated indicates indicating indication indicator indices
 indirect indirectly individual individually indkey indonesia industries
-inefficient ineg inet inf infin infinite infinity infix inflate inflater info
+inefficient ineg inet inf inferred infin infinite infinity infix inflate inflater info
 inform information informational informed informix informs informtn infos
 infrastructure infringe infringed infringement infringements infringes infringing
 inherent inherit inheritance inherited inherits ini init initial initialization
@@ -434,7 +434,7 @@ obligation obligations observer obsolete obtain obtained obtains obviously
 occasionally occupied occupies occupy occur occurred occurrence occurrences occurs
 ocirc octal octet october octype odbc odbcad odd odg off offending offer offered
 offering offers office official offline offset offsets often ogc ograve ohloh oid okay
-okra olap olapsys old older oldest oline oliver olivier omega omicron omissions
+okra olap olapsys old older oldest oline oliver olivier omega omicron omissions omit
 omitted omitting once onchange onclick one ones onfocus ongoing onkeydown onkeyup
 online onload only onmousedown onmousemove onmouseout onmouseover onmouseup
 onreadystatechange onresize onscroll onsubmit onto ontology ontoprise oome oops
@@ -477,7 +477,7 @@ pointing points poker poland polar pole poleposition policies policy polish poll
 polling polski poly polygon pom pondered poodle pool poolable pooled pooling
 pools poor poormans pop popular populate populated population popup port
 portability portable portal portals ported porting portion portions portlet ports
-portugal portugu pos position positioned positions positive pospichal possibility
+portugal portugu pos position positioned positions positional positive pospichal possibility
 possible possibly post postal postfix postgre postgres postgresql posting
 postmaster potential potentially poultry pound pow power powerful poweroff
 practicable practice prd pre prec precedence precision precisions predicate