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From banda...@apache.org
Subject svn commit: r178006 [1/3] - in /incubator/derby/code/trunk/java: client/org/apache/derby/client/am/ testing/org/apache/derbyTesting/functionTests/master/ testing/org/apache/derbyTesting/functionTests/master/DerbyNetClient/ testing/org/apache/derbyTesting/functionTests/master/jdk14/ testing/org/apache/derbyTesting/functionTests/suites/ testing/org/apache/derbyTesting/functionTests/tests/lang/
Date Mon, 23 May 2005 19:33:35 GMT
Author: bandaram
Date: Mon May 23 12:33:33 2005
New Revision: 178006

URL: http://svn.apache.org/viewcvs?rev=178006&view=rev
Log:
Support for Updatable Resultsets in Derby Client.

Following is a brief description of the actual changes that are going into the patch
1) After updateRow(provided updateXXX were issued on the row before updateRow) and deleteRow,
position the resultset to right before the next row. This matches the embedded driver behavior.
2)If ResultSet is not positioned on a row and user issues updateRow (w/o prior updateXXX),
then throw an exception that it is not a valid operation. This matches the embedded driver
behavior.
3)Made changes to DNC so that it does not require all the updatable columns in the sql to
be modified with updateXXX prior to updateRow. This matches the embedded driver behavior.
4)To preserve case sensitivity and spaces in the names, put quotes around database object
names like table name, column name, cursor name etc. Similar to embedded driver.(Positive
Test31a, Test31b)
5)For a select sql like, select 2, c11 from t1, Derby has null for table name and schema name
for column 2. DNC needs to check for these nulls to avoid null pointer exception.

Submitted by Mamta Satoor(msatoor@gmail.com)

Modified:
    incubator/derby/code/trunk/java/client/org/apache/derby/client/am/ResultSet.java
    incubator/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/DerbyNetClient/updatableResultSet.out
    incubator/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/jdk14/updatableResultSet.out
    incubator/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/master/updatableResultSet.out
    incubator/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/suites/DerbyNet.exclude
    incubator/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/updatableResultSet.java

Modified: incubator/derby/code/trunk/java/client/org/apache/derby/client/am/ResultSet.java
URL: http://svn.apache.org/viewcvs/incubator/derby/code/trunk/java/client/org/apache/derby/client/am/ResultSet.java?rev=178006&r1=178005&r2=178006&view=diff
==============================================================================
--- incubator/derby/code/trunk/java/client/org/apache/derby/client/am/ResultSet.java (original)
+++ incubator/derby/code/trunk/java/client/org/apache/derby/client/am/ResultSet.java Mon May
23 12:33:33 2005
@@ -2368,43 +2368,75 @@
             if (agent_.loggingEnabled()) {
                 agent_.logWriter_.traceEntry(this, "updateRow");
             }
-            updateRowX();
+            //If updateXXX were issued on the row before updateRow, then
+            //position the ResultSet to right before the next row after updateRow
+            if (updateRowX())
+                isValidCursorPosition_ = false;
         }
     }
 
-    private void updateRowX() throws java.sql.SQLException {
+    //if no updateXXX were issued before this updateRow, then return false
+    private boolean updateRowX() throws java.sql.SQLException {
         checkForClosedResultSet();
         if (isOnInsertRow_ || resultSetConcurrency_ == java.sql.ResultSet.CONCUR_READ_ONLY)
{
             throw new SqlException(agent_.logWriter_, "This method cannot be invoked while
the cursor is on the insert " +
                     "row or if the concurrency of this ResultSet object is CONCUR_READ_ONLY.");
         }
 
-        // No-op if none of the columns were updated and updateRow() is called, just return.
+        //if not on a valid row, then do not accept updateXXX calls
+        if (!isValidCursorPosition_)
+            throw new SqlException(agent_.logWriter_, "Invalid operation to " +
+                    "update at current cursor position");
+
+        // If no updateXXX has been called on this ResultSet object, then
+        // updatedColumns_ will be null and hence no action required
         if (updatedColumns_ == null) {
-            return;
+            return false;
         }
 
-        if (preparedStatementForUpdate_ == null) {
-            getPreparedStatementForUpdate();
+        // updateXXX has been called on this ResultSet object, but check if it
+        // has been called on the current row. If no column got updated on this
+        // current row, then just return.
+        boolean didAnyColumnGetUpdated = false;
+        for (int i=0; i < updatedColumns_.length; i++) {
+            if (columnUpdated_[i]) {
+                didAnyColumnGetUpdated = true;
+                break;
+            }
         }
+        if (didAnyColumnGetUpdated == false)
+            return false;
+
+        // User might not be updating all the updatable columns selected in the
+        // select sql and hence every updateRow on the same ResultSet can be
+        // potentially different than the previous one. Because of that, we
+        // should get a new prepared statement to do updates every time
+        getPreparedStatementForUpdate();
 
         // build the inputs array for the prepared statement for update
+        int paramNumber = 0;
         for (int i = 0; i < updatedColumns_.length; i++) {
             if (resultSetMetaData_.sqlxUpdatable_[i] == 1) {
+                // Since user may choose not to update all the columns in the
+                // select list, check first if the column has been updated
+                if (columnUpdated_[i] == false)
+                    continue;
+                paramNumber++;
+
                 // column is updated either if the updatedColumns_ entry is not null,
                 // or if the updatedColumns_ entry is null, but columnUpdated_ boolean is
                 // set to true, which means columns is updated to a null.
                 if (updatedColumns_[i] != null ||
                         (updatedColumns_[i] == null && columnUpdated_[i])) {
-                    preparedStatementForUpdate_.setInput(i + 1, updatedColumns_[i]);
+                    preparedStatementForUpdate_.setInput(paramNumber, updatedColumns_[i]);
                 } else {
                     // Check if the original column is null.  Calling CrossConverters.setObject
on a null
                     // column causes "Data Conversion" Exception.
                     Object originalObj = getObject(i + 1);
                     if (originalObj == null) {
-                        preparedStatementForUpdate_.setInput(i + 1, null);
+                        preparedStatementForUpdate_.setInput(paramNumber, null);
                     } else {
-                        preparedStatementForUpdate_.setInput(i + 1, agent_.crossConverters_.setObject(resultSetMetaData_.types_[i],
originalObj));
+                        preparedStatementForUpdate_.setInput(paramNumber, agent_.crossConverters_.setObject(resultSetMetaData_.types_[i],
originalObj));
                     }
                 }
             }
@@ -2423,6 +2455,7 @@
             cancelRowUpdates();
             throw e;
         }
+        return true;
     }
 
     public void deleteRow() throws java.sql.SQLException {
@@ -2431,6 +2464,10 @@
                 agent_.logWriter_.traceEntry(this, "deleteRow");
             }
             deleteRowX();
+            //the cursor is not positioned on the deleted row after deleteRow.
+            //User needs to issue ResultSet.next to reposition the ResultSet
+            //on a valid row
+            isValidCursorPosition_ = false;
         }
     }
 
@@ -2502,6 +2539,11 @@
                         "row or if this ResultSet object has a concurrency of CONCUR_READ_ONLY.");
             }
 
+            // if not on a valid row, then do not accept cancelRowUpdates call
+            if (!isValidCursorPosition_)
+                throw new SqlException(agent_.logWriter_, "Invalid operation " +
+                        "at current cursor position.");
+
             // if updateRow() has already been called, then cancelRowUpdates should have
             // no effect.  updateRowCalled_ is reset to false as soon as the cursor moves
to a new row.
             if (!updateRowCalled_) {
@@ -3041,8 +3083,6 @@
         boolean foundOneUpdatedColumnAlready = false;
         String updateString = "UPDATE " + getTableName() + " SET ";
 
-        // The update tablename ... where current of cursorname for Cloudscape has
-        // to provide columns as columnname1 = ?, columnname2 = ?
         for (column = 1; column <= resultSetMetaData_.columns_; column++) {
             if (columnUpdated_[column - 1]) {
                 if (foundOneUpdatedColumnAlready) {
@@ -3069,8 +3109,8 @@
     private String buildDeleteString() throws SqlException {
         String deleteString = "DELETE FROM ";
 
-        // build the update string using the server's cursor name
-        deleteString += (getTableName() + " WHERE CURRENT OF " + getServerCursorName());
+        // build the delete string using the server's cursor name
+        deleteString += (getTableName() + " WHERE CURRENT OF \"" + getServerCursorName()
+ "\"");
 
         if (isRowsetCursor_) {
             deleteString += " FOR ROW ? OF ROWSET";
@@ -3079,17 +3119,41 @@
         return deleteString;
     }
 
-    private String getTableName() {
+    //Go through all the columns in the select list to see if we can find a
+    //base table column and use that column's metadata to get the table name
+    //But, it is possible to have a sql of the form
+    //select 1,2 from t1 for update
+    //This sql will not be a good candidate for updateXXX calls(both in embedded
+    //and Network Server mode) since there is no updatable column in the select
+    //list. But a user can use a sql like that to issue deleteRow. In Network
+    //Server mode though, this sql will fail for deleteRow because none of the
+    //columns are from base table and w/o a base table column, there is no way
+    //to find the table name for delete
+    private String getTableName() throws SqlException {
         String tableName = "";
-        if (resultSetMetaData_.sqlxRdbnam_[0] != null &&
-                !resultSetMetaData_.sqlxRdbnam_[0].equals(""))      // catalog
+        int baseTableColumn = 0;
+        int totalColumns = resultSetMetaData_.getColumnCount();
+        for (; baseTableColumn < totalColumns; baseTableColumn++) {
+            if (resultSetMetaData_.sqlxSchema_[baseTableColumn] != null)
+                break;
+        }
+
+        //if following true, then there are no base table columns in select list
+        if (baseTableColumn == totalColumns)
+            baseTableColumn = 0;
+
+        if (resultSetMetaData_.sqlxRdbnam_[baseTableColumn] != null &&
+                !resultSetMetaData_.sqlxRdbnam_[baseTableColumn].equals(""))      // catalog
         {
-            tableName += resultSetMetaData_.sqlxRdbnam_[0].trim() + ".";
+            tableName += "\"" + resultSetMetaData_.sqlxRdbnam_[baseTableColumn] + "\".";
+        }
+        //dervied column like select 2 from t1, has null schema and table name
+        if (resultSetMetaData_.sqlxSchema_[baseTableColumn] != null && !resultSetMetaData_.sqlxSchema_[baseTableColumn].equals(""))
{
+            tableName += "\"" + resultSetMetaData_.sqlxSchema_[baseTableColumn] + "\".";
         }
-        if (!resultSetMetaData_.sqlxSchema_[0].equals("")) {
-            tableName += resultSetMetaData_.sqlxSchema_[0].trim() + ".";
+        if (resultSetMetaData_.sqlxBasename_[baseTableColumn] != null) {
+            tableName += "\"" + resultSetMetaData_.sqlxBasename_[baseTableColumn] + "\"";
         }
-        tableName += resultSetMetaData_.sqlxBasename_[0].trim();
         return tableName;
     }
 
@@ -3157,6 +3221,11 @@
         if (resultSetMetaData_.sqlxUpdatable_ == null || resultSetMetaData_.sqlxUpdatable_[column
- 1] != 1) {
             throw new SqlException(agent_.logWriter_, "Column not updatable");
         }
+
+        //if not on a valid row, then do not accept updateXXX calls
+        if (!isValidCursorPosition_)
+            throw new SqlException(agent_.logWriter_, "Invalid operation to " +
+                    "update at current cursor position");
     }
 
     final void checkForValidColumnIndex(int column) throws SqlException {



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