Open SQL

Scope of Open SQL

Open SQL refers to the subset

• SELECT
  

• OPEN CURSOR, FETCH NEXT CURSOR, CLOSE CURSOR
  

• INSERT
  

• UPDATE
  

• MODIFY
  

• DELETE

of ABAP statements that enable direct access to data of the central database of the current ABAP system. The Open SQL statements form the DMLSQL in ABAP, which is supported by all database systems.

Database interface

The statements of Open SQL are converted to database-specific SQL in the Open SQL interface of the database interface. They are then transferred to the database system and executed there. Open SQL statements can be used to exclusively access database tables that are declared in the ABAP Dictionary. It is also possible to access these using views.

Database access

Each Open SQL statement is synonymous with accessing the database. This applies in particularly with SELECT statements that end in ENDSELECT. Data to be read and to be written is transported in packages between the database server and the current application server. You can configure the size of the packages using profile parameters (for example, the standard value for Oracle is 65 KB). The number of characters that can be transported in one package depends on whether the system is a Unicode system or a non-Unicode system.

Client handling

Open SQL works with automatic client handling. When client-specific database tables are accessed, the client identifier cannot be explicitly specified, or is overwritten with the ID of the current client by the runtime environment. You can deactivate automatic client handling using the addition CLIENT SPECIFIED.

LUW

When using the change statements (INSERT, UPDATE, MODIFY and DELETE), it is important to keep data storage consistent. The LUW concept is designed for this purpose. In application programs of an SAP system, the implicit database LUWs are normally not sufficient for consistent data storage. Instead, you need to program explicit SAP LUWs, which normally contain several database LUWs (see the section on data consistency).

Performance

See Performance advice for Open SQL.

Coding examples

See Examples for using Open SQL.

Obsolete database access methods

There are also obsolete forms of OpenSQL statements, and obsolete statements for accessing database tables, which do not belong in the scope of Open SQL.