Reading to a Buffer

This tutorial describes how to read the data from the table into a buffer.

Introduction

This query allows you to retrieve the data in a field. You can retrieve one entry or multiple entries in the same column by executing the query in a loop.

Basic procedure

The high level steps to read the data into the buffer are shown here:

Configure the SQL statement.
Allocate memory and copy data.
Deallocate memory.

Detailed steps

The steps to read data to a buffer are as follows:

Configure the SQL statement

Instantiate an RSqlStatement object and declare the variables as required.

RSqlStatement myStatement; +TInt err;

Allocate memory and copy data

To retrieve all the entries, use a loop. The steps to be performed within the loop are as described below:

Instantiate an object of the RBuf class.
while((err = myStatement.Next()) == KSqlAtRow) + { + RBuf myBuffer;
Allocate enough memory to hold the column data using the CreateL() function as shown below.
err = myBuffer.CreateL(myStatement.ColumnSize(columnIndex));
Copy the data from the table into the buffer using ColumnBinary() function.
err = myStatement.ColumnBinary(myColumnIndex,myBuffer); + ... + // process data

Deallocate memory

Deallocate the memory assigned to the RBuf object.

myBuffer.Close(); + }