PreparedStatement.getMetaData() was not always consistent with resulting ResultSet.getMetaData().

h2/src/docsrc/html/changelog.html

@@ -18,7 +18,8 @@ Change Log
 <h1>Change Log</h1>
 
 <h2>Next Version (unreleased)</h2>
-<ul><li>The build tool now uses JAVA_HOME for javac as well. Issue 233.
+<ul><li>PreparedStatement.getMetaData() was not always consistent with resulting ResultSet.getMetaData(). 
+</li><li>The build tool now uses JAVA_HOME for javac as well. Issue 233.
 </li><li>Opening and closing encrypted databases is now much faster.
 </li><li>H2 Console: new experimental feature to support file download and upload,
     but only if there is a directory called "transfer" in the current working directory.

h2/src/main/org/h2/command/dml/Call.java

@@ -11,11 +11,10 @@ import org.h2.command.CommandInterface;
 import org.h2.command.Prepared;
 import org.h2.engine.Session;
 import org.h2.expression.Expression;
-import org.h2.expression.ExpressionColumn;
 import org.h2.expression.ExpressionVisitor;
+import org.h2.message.DbException;
 import org.h2.result.LocalResult;
 import org.h2.result.ResultInterface;
-import org.h2.table.Column;
 import org.h2.value.Value;
 import org.h2.value.ValueArray;
 import org.h2.value.ValueResultSet;
@@ -26,7 +25,6 @@ import org.h2.value.ValueResultSet;
  */
 public class Call extends Prepared {
 
-
     private Expression expression;
     private Expression[] expressions;
 
@@ -35,7 +33,14 @@ public class Call extends Prepared {
     }
 
     public ResultInterface queryMeta() {
-        LocalResult result = new LocalResult(session, expressions, 1);
+        int expressionType = expression.getType();
+        LocalResult result;
+        if (expressionType == Value.RESULT_SET || expressionType == Value.ARRAY) {
+            Expression[] expr = expression.getExpressionColumns(session);
+            result = new LocalResult(session, expr, expr.length);
+        } else {
+            result = new LocalResult(session, expressions, 1);
+        }
         result.done();
         return result;
     }
@@ -60,18 +65,17 @@ public class Call extends Prepared {
     public ResultInterface query(int maxrows) {
         setCurrentRowNumber(1);
         Value v = expression.getValue(session);
-        if (v.getType() == Value.RESULT_SET) {
+        switch (expression.getType()) {
+        case Value.RESULT_SET:
             ResultSet rs = ((ValueResultSet) v).getResultSet();
             return LocalResult.read(session, rs, maxrows);
-        } else if (v.getType() == Value.ARRAY) {
+        case Value.ARRAY:
             Value[] list = ((ValueArray) v).getList();
-            Expression[] expr = new Expression[list.length];
-            for (int i = 0; i < list.length; i++) {
-                Value e = list[i];
-                Column col = new Column("C" + (i + 1), e.getType(), e.getPrecision(), e.getScale(), e.getDisplaySize());
-                expr[i] = new ExpressionColumn(session.getDatabase(), col);
+            Expression[] expr = expression.getExpressionColumns(session);
+            if (expr.length != list.length) {
+                throw DbException.throwInternalError();
             }
-            LocalResult result = new LocalResult(session, expr, list.length);
+            LocalResult result = new LocalResult(session, expr, expr.length);
             result.addRow(list);
             result.done();
             return result;

h2/src/main/org/h2/expression/Expression.java

@@ -6,12 +6,18 @@
  */
 package org.h2.expression;
 
+import java.sql.ResultSet;
+import java.sql.ResultSetMetaData;
+import java.sql.SQLException;
+import org.h2.engine.Database;
 import org.h2.engine.Session;
 import org.h2.table.Column;
 import org.h2.table.ColumnResolver;
 import org.h2.table.TableFilter;
 import org.h2.util.StringUtils;
+import org.h2.value.DataType;
 import org.h2.value.Value;
+import org.h2.value.ValueArray;
 
 /**
  * An expression is a operation, a value, or a function in a query.
@@ -292,4 +298,58 @@ public abstract class Expression {
         return getSQL();
     }
 
+    /**
+     * If this expression consists of column expressions it should return them.
+     * 
+     * @return array of expression columns if applicable, null otherwise
+     */
+    public Expression[] getExpressionColumns(Session session) {
+        return null;
+    }
+
+    /**
+     * Extracts expression columns from ValueArray
+     * 
+     * @param session the current session
+     * @param value the value to extract columns from
+     * @return array of expression columns
+     */
+    public static Expression[] getExpressionColumns(Session session, ValueArray value) {
+        Value[] list = value.getList();
+        ExpressionColumn[] expr = new ExpressionColumn[list.length];
+        for (int i = 0; i < list.length; i++) {
+            Value v = list[i];
+            Column col = new Column("C" + (i + 1), v.getType(), v.getPrecision(), v.getScale(),
+                    v.getDisplaySize());
+            expr[i] = new ExpressionColumn(session.getDatabase(), col);
+        }
+        return expr;
+    }
+
+    /**
+     * Extracts expression columns from the given result set. 
+     * 
+     * @param session the session
+     * @param rs the result set
+     * @return an array of expression columns 
+     * @throws SQLException
+     */
+    public static Expression[] getExpressionColumns(Session session, ResultSet rs) throws SQLException {
+        ResultSetMetaData meta = rs.getMetaData();
+        int columnCount = meta.getColumnCount();
+        Expression[] expressions = new Expression[columnCount];
+        Database db = session == null ? null : session.getDatabase();
+        for (int i = 0; i < columnCount; i++) {
+            String name = meta.getColumnLabel(i + 1);
+            int type = DataType.convertSQLTypeToValueType(meta.getColumnType(i + 1));
+            int precision = meta.getPrecision(i + 1);
+            int scale = meta.getScale(i + 1);
+            int displaySize = meta.getColumnDisplaySize(i + 1);
+            Column col = new Column(name, type, precision, scale, displaySize);
+            Expression expr = new ExpressionColumn(db, col);
+            expressions[i] = expr;
+        }
+        return expressions;
+    }
+
 }

h2/src/main/org/h2/expression/ExpressionList.java

@@ -7,6 +7,7 @@
 package org.h2.expression;
 
 import org.h2.engine.Session;
+import org.h2.table.Column;
 import org.h2.table.ColumnResolver;
 import org.h2.table.TableFilter;
 import org.h2.util.StatementBuilder;
@@ -108,4 +109,15 @@ public class ExpressionList extends Expression {
         return cost;
     }
 
+    public Expression[] getExpressionColumns(Session session) {
+        ExpressionColumn[] expr = new ExpressionColumn[list.length];
+        for (int i = 0; i < list.length; i++) {
+            Expression e = list[i];
+            Column col = new Column("C" + (i + 1), e.getType(), e.getPrecision(), e.getScale(),
+                    e.getDisplaySize());
+            expr[i] = new ExpressionColumn(session.getDatabase(), col);
+        }
+        return expr;
+    }
+
 }

h2/src/main/org/h2/expression/JavaFunction.java

@@ -6,16 +6,19 @@
  */
 package org.h2.expression;
 
+import java.sql.SQLException;
 import org.h2.command.Parser;
 import org.h2.constant.SysProperties;
 import org.h2.engine.Constants;
 import org.h2.engine.FunctionAlias;
 import org.h2.engine.Session;
+import org.h2.message.DbException;
 import org.h2.table.ColumnResolver;
 import org.h2.table.TableFilter;
 import org.h2.util.StatementBuilder;
 import org.h2.value.DataType;
 import org.h2.value.Value;
+import org.h2.value.ValueArray;
 import org.h2.value.ValueNull;
 import org.h2.value.ValueResultSet;
 
@@ -154,4 +157,18 @@ public class JavaFunction extends Expression implements FunctionCall {
         return functionAlias.isDeterministic();
     }
 
+    public Expression[] getExpressionColumns(Session session) {
+        switch (getType()) {
+        case Value.RESULT_SET:
+            ValueResultSet vrs = getValueForColumnList(session, getArgs());
+            try {
+                return getExpressionColumns(session, vrs.getResultSet());
+            } catch (SQLException e) {
+                throw DbException.convert(e);
+            }
+        case Value.ARRAY:
+            return getExpressionColumns(session, (ValueArray) getValue(session));
+        }
+        return super.getExpressionColumns(session);
+    }
 }

h2/src/main/org/h2/expression/Subquery.java

@@ -6,6 +6,7 @@
  */
 package org.h2.expression;
 
+import java.util.ArrayList;
 import org.h2.command.dml.Query;
 import org.h2.constant.ErrorCode;
 import org.h2.engine.Session;
@@ -24,6 +25,7 @@ import org.h2.value.ValueNull;
 public class Subquery extends Expression {
 
     private Query query;
+    private Expression expression;
 
     public Subquery(Query query) {
         this.query = query;
@@ -93,7 +95,20 @@ public class Subquery extends Expression {
     }
 
     private Expression getExpression() {
-        return query.getExpressions().get(0);
+        if (expression == null) {
+            ArrayList<Expression> exprs = query.getExpressions();
+            int columnCount = query.getColumnCount();
+            if (columnCount == 1) {
+                expression = exprs.get(0);
+            } else {
+                Expression[] list = new Expression[columnCount];
+                for (int i = 0; i < columnCount; i++) {
+                    list[i] = exprs.get(i);
+                }
+                expression = new ExpressionList(list);
+            }
+        }
+        return expression;
     }
 
     public boolean isEverything(ExpressionVisitor visitor) {
@@ -108,4 +123,7 @@ public class Subquery extends Expression {
         return 10 + (int) (10 * query.getCost());
     }
 
+    public Expression[] getExpressionColumns(Session session) {
+        return getExpression().getExpressionColumns(session);
+    }
 }

h2/src/main/org/h2/expression/TableFunction.java

@@ -6,6 +6,7 @@
  */
 package org.h2.expression;
 
+import java.sql.SQLException;
 import java.util.ArrayList;
 import org.h2.constant.ErrorCode;
 import org.h2.engine.Database;
@@ -148,4 +149,11 @@ public class TableFunction extends Function {
         return rowCount;
     }
 
+    public Expression[] getExpressionColumns(Session session) {
+        try {
+            return getExpressionColumns(session, getTable(session, getArgs(), true, false).getResultSet());
+        } catch (SQLException e) {
+            throw DbException.convert(e);
+        }
+    }
 }

h2/src/main/org/h2/expression/ValueExpression.java

@@ -12,6 +12,7 @@ import org.h2.message.DbException;
 import org.h2.table.ColumnResolver;
 import org.h2.table.TableFilter;
 import org.h2.value.Value;
+import org.h2.value.ValueArray;
 import org.h2.value.ValueBoolean;
 import org.h2.value.ValueNull;
 
@@ -153,4 +154,10 @@ public class ValueExpression extends Expression {
         return 0;
     }
 
+    public Expression[] getExpressionColumns(Session session) {
+        if (getType() == Value.ARRAY) {
+            return getExpressionColumns(session, (ValueArray) getValue(session));
+        }
+        return super.getExpressionColumns(session);
+    }
 }

h2/src/main/org/h2/result/LocalResult.java

@@ -7,16 +7,12 @@
 package org.h2.result;
 
 import java.sql.ResultSet;
-import java.sql.ResultSetMetaData;
 import java.sql.SQLException;
 import java.util.ArrayList;
 import org.h2.constant.SysProperties;
-import org.h2.engine.Database;
 import org.h2.engine.Session;
 import org.h2.expression.Expression;
-import org.h2.expression.ExpressionColumn;
 import org.h2.message.DbException;
-import org.h2.table.Column;
 import org.h2.util.New;
 import org.h2.util.ValueHashMap;
 import org.h2.value.DataType;
@@ -83,7 +79,7 @@ public class LocalResult implements ResultInterface {
      */
     public static LocalResult read(Session session, ResultSet rs, int maxrows) {
         try {
-            Expression[] cols = getExpressionColumns(session, rs);
+            Expression[] cols = Expression.getExpressionColumns(session, rs);
             int columnCount = cols.length;
             LocalResult result = new LocalResult(session, cols, columnCount);
             for (int i = 0; (maxrows == 0 || i < maxrows) && rs.next(); i++) {
@@ -101,24 +97,6 @@ public class LocalResult implements ResultInterface {
         }
     }
 
-    private static Expression[] getExpressionColumns(Session session, ResultSet rs) throws SQLException {
-        ResultSetMetaData meta = rs.getMetaData();
-        int columnCount = meta.getColumnCount();
-        Expression[] expressions = new Expression[columnCount];
-        Database db = session == null ? null : session.getDatabase();
-        for (int i = 0; i < columnCount; i++) {
-            String name = meta.getColumnLabel(i + 1);
-            int type = DataType.convertSQLTypeToValueType(meta.getColumnType(i + 1));
-            int precision = meta.getPrecision(i + 1);
-            int scale = meta.getScale(i + 1);
-            int displaySize = meta.getColumnDisplaySize(i + 1);
-            Column col = new Column(name, type, precision, scale, displaySize);
-            Expression expr = new ExpressionColumn(db, col);
-            expressions[i] = expr;
-        }
-        return expressions;
-    }
-
     /**
      * Create a shallow copy of the result set. The data and a temporary table
      * (if there is any) is not copied.