UltraLite C++ User's Guide
  Understanding UltraLite Development
    Accessing and manipulating data with dynamic SQL

Data manipulation: INSERT, UPDATE and DELETE

To perform SQL Data Manipulation Language operations (INSERT, UPDATE, and DELETE), you carry out the following sequence of operations:

1. Prepare the statement.

   You can indicate parameters in the statement using the ? character.

2. Assign values for parameters in the statement.

   For any INSERT, UPDATE or DELETE, each ? is referred to by its ordinal position in the prepared statement.

3. Execute the statement.

4. Repeat steps 2 and 3 as required.

To perform INSERT operations using ExecuteStatement:

1. Declare a PreparedStatement.

   PreparedStatement * prepStmt;

2. Assign a SQL statement to the PreparedStatement object.

   ULValue sqltext( 
       "INSERT INTO MyTable(MyColumn) values (?)" );
   prepStmt = conn->PrepareStatement( sqltext );

3. Assign input parameter values for the statement.

   The following code shows a string parameter.

   ULValue newValue( "string-value" );
   prepStmt->SetParameter( 1, newValue );

4. Execute the statement.

   The return value indicates the number of rows affected by the statement.

   ul_s_long rowsInserted;
   rowsInserted = prepStmt->ExecuteStatement();

5. Commit the change.

   conn->Commit();

To perform UPDATE operations using ExecuteStatement:

1. Declare a PreparedStatement.

   PreparedStatement * prepStmt;

2. Assign a statement to the PreparedStatement object.

   ULValue sqltext(
      "UPDATE MyTable SET MyColumn1 = ? WHERE MyColumn2 = ?" );
   prepStmt = conn->PrepareStatement( sqltext );

3. Assign input parameter values for the statement.

   ULValue newValue( new-value );
   ULValue oldValue( old-value );
   stmt->SetParameter( 1, newValue );
   stmt->SetParameter( 2, oldValue );

4. Execute the statement.

   long rowsUpdated = prepStmt->ExecuteStatement();

5. Commit the change.

   conn->Commit();

To perform DELETE operations using ExecuteStatement:

1. Declare a PreparedStatement.

   PreparedStatement * prepStmt;

2. Assign a statement to the PreparedStatement object.

   ULValue sqltext(
      "DELETE FROM MyTable WHERE MyColumn = ?" );
   prepStmt = conn->PrepareStatement( sqltext );

3. Assign input parameter values for the statement.

   ULValue deleteValue( old-value );
   prepStmt->SetParameter( 1, deleteValue );

4. Execute the statement.

   long rowsDeleted = prepStmt->ExecuteStatement();

5. Commit the change.

   conn->Commit();