open sql and native sql

[Former Member]

hi,

in SAP which type we will use native or open ,then what is the difference between them.pls tell me detailly?

[Former Member]

Hi,

In SAP we are using OPEN SQL statement.

The following Data Will give you detailed information.

If you write a business application, there is always a database on backend. So SAP R/3 uses a database too. It is a

special database? No. SAP uses standard databases like Oracle, IBM DB2, MS SQL Server, etc. If you have a database on backend, it is inevitable that you must use SQL. SAP uses SQL to select, insert and update data inside database. However, the problem is that if you use different databases, your code whatever it is whether ABAP or not, SQL can vary. In that situation although programmers tend to use Standard SQL which is valid for all databases, the problems sometimes occur to switch one database to different database. What I am trying to say is SAP had invented a new way to solve this problem: Open SQL

Open SQL

Open SQL consists of a set of ABAP statements that perform operation on central database in the R/3 System. The results of the operations and any error messages are independent of the database system in use. Open SQL thus provides a uniform syntax and semantics for all of database systems supported by SAP. ABAP programs that only use Open SQL statements will work in any SAP R/3 System, regardless of the database system in use. Open SQL statements can work with database tables that have been created in the ABAP Dictionary.

The method actually is simple that when a programmer writes an ABAP program with Open SQL statements, the kernel SAP programs convert Open SQL statements to real / native SQL statements for database in use. So like that write once, run for all databases and even for all operating systems. Like Java’s “Write Once. Run Anywhere“. Think about Java, even the Java uses the same principal that is Java Virtual Machine which looks like SAP’s kernel programs. Right? Can we say SAP did “Write Once. Run Anywhere” before Java?

Open SQL contains the following keywords:

SELECT - Reads data from database tables.

INSERT - Adds lines to database tables.

UPDATE - Changes the contents of lines of database tables.

MODIFY - Inserts lines into database tables or changes the contents of existing lines.

DELETE - Delete lines from database tables.

OPEN CURSOR, FETCH, CLOSE CURSOR - Reads lines of database tables using the cursor.

All Open SQL statements fill the following two system fields with return codes:

SY-SUBRC

After every Open SQL statement, the system field SY-SUBRC contains 0 if the operation was successful, a value other than 0 if not.

SY-DBCNT

After an OPEN SQL statement, the system field SY-DBCNT contains the number of database lines processed.

Native SQL

Native SQL is real SQL for database in use. It means beside OPEN SQL, if you need you can use the native SQL for databases. Native SQL allows you to use database-specific SQL statements in an ABAP program. This means that you can use database tables that are not administered by the ABAP Dictionary, and therefore integrate data that is not part of the R/3 System.

As a rule, an ABAP program containing database-specific SQL statements will not run under different database systems. If your program will be used on more than one database platform, only use Open SQL statements.

I have never used Native SQL in my experiences more than 6 years for ABAP programming. I tried it, you can be sure it works. All ABAP programs in SAP R/3 System have been written with Open SQL. But I sometimes encountered Native SQL statements in original ABAP programs. I think if you have a different database instant in the same database, you can use Native SQL statement to connect and do operation on this database instant. Let me clarify this a little bit. Let’s assume you have an SAP R/3 system that uses Oracle database instant ORC1. You have an other application, even it uses the same database Oracle, but as normally different database instant ORC2. So like data inside ABAP program, you can use Native SQL statements to connect ORC2, non-SAP database instant, to integrate SAP R/3 and non-SAP system. It is kind of an integration activity.

If you create a table by using database tools, without ABAP Dictionary, you are not able to use Open SQL to reach this table. You just can use Native SQL to do that.

Native SQL statements bypass the R/3 database interface. There is no table logging, and no synchronization with the database buffer on the application server. For this reason, you should, wherever possible, use Open SQL to change database tables declared in the ABAP Dictionary. In particular, tables declared in the ABAP Dictionary that contain log columns with types LCHR and LRAW should only be addressed using Open SQL, since the columns contain extra, database-specific length information for the column. Native SQL does not take this information into account, and may therefore produce incorrect results. Furthermore, Native SQL does not support automatic client handling. Instead, you must treat client fields like any other.

To ensure that transactions in the R/3 System are consistent, you should not use any transaction control statements (COMMIT, ROLLBACK WORK), or any statements that set transaction parameters (isolation level…) using Native SQL.

Using Native SQL, you can

Transfer values from ABAP fields to the database

Read data from the database and process it in ABAP programs.

Native SQL works without the administrative data about database tables stored in the ABAP Dictionary. Consequently, it cannot perform all of the consistency check used in Open SQL. This places a larger degree responsibility on application developers to work with ABAP fields of the correct type. You should always ensure that the ABAP data type and the type of database column are identical.

Native SQL Advantages and Disadvantages - EXEC SQL statement

Advantages

Tables are not declared in ABAP Dictionary can be accessed. (e.g. Tables belonging to sys or system user of Oracle, etc.)

To use some of the special features supported by the database-specific SQL. (e.g. Passing hints to Oracle optimizer.)

Disadvanteges

No syntax check is performed whatever is written between EXEC and ENDEXEC.

ABAP program containing database-specific SQL statements will not run under different database systems.

There is no automatic clien handling for client dependent tables.

Care has to be taken during migration to higher versions.

*If useful reward with points*

[raymond_giuseppi]

Look at SAP documentation

[Database Accesses of the NetWeaver AS ABAP|http://help.sap.com/saphelp_nw70/helpdata/en/fc/eb3b8b358411d1829f0000e829fbfe/frameset.htm]

Open SQL
Open SQL statements are a fully integrated subset of Standard SQL within ABAP. They enable the ABAP programs to access data irrespective of the database system installed. Open SQL consists of the Data Manipulation Language (DML) part of Standard SQL; in other words, it allows you to read (SELECT) and change (INSERT, UPDATE, DELETE) data.
Open SQL also goes beyond Standard SQL to provide statements that, in conjunction with other ABAP constructions, can simplify or speed up database access. It also allows you to buffer certain tables on the application server, saving excessive database access. In this case, the database interface is responsible for comparing the buffer with the database. Buffers are partly stored in the working memory of the current work process, and partly in the shared memory for all work processes on an application server. In SAP systems that are distributed across more than one application server, the data in the various buffers is synchronized at set intervals by buffer management. When buffering the database, you must remember that data in the buffer is not always up to date. For this reason, you should only use the buffer for data which does not often change. You specify whether a table can be buffered in its definition in the ABAP Dictionary.
Native SQL
Native SQL is only loosely integrated into ABAP, and allows access to all of the functions contained in the programming interface of the respective database system. Unlike Open SQL statements, Native SQL statements are not checked and converted, but instead are sent directly to the database system. When you use Native SQL, the function of the database-dependent layer is minimal. Programs that use Native SQL are specific to the database system for which they were written. When developing generally valid ABAP applications, you should – as far as possible – avoid using Native SQL. In some components of the SAP System, Native SQL is used – for example, in the ABAP Dictionary for creating or changing tables.

Regards

[Former Member]

Suppose you are using the oracle DB then in the SAP editor you write the Oracle statements, it is native code.

Native code : Using that DataBase language commands in the SAP editor. This is very faster execution because it directly executed in that DB.

Open SQL : Here we can write the code in SAP language(what ever it is the DB is) then internally it converts this commands to that DB related commands at runtime, it takes some time for converting.

[Former Member]

The difference is:

OPEN SQL - Open SQL consists of a set of ABAP statements that perform operations on the central database in the R/3 System. The results of the operations and any error messages are independent of the database system in use. Open SQL thus provides a uniform syntax and semantics for all of the database systems supported by SAP. ABAP programs that only use Open SQL statements will work in any R/3 System, regardless of the database system in use. Open SQL statements can only work with database tables that have been created in the ABAP Dictionary.

NATIVE SQL - Open SQL allows you to access database tables declared in the ABAP Dictionary regardless of the database platform that you R/3 System is using. Native SQL allows you to use database-specific SQL statements in an ABAP program. This means that you can use database tables that are not administered by the ABAP Dictionary, and therefore integrate data that is not part of the R/3 System.

Check this link.

Reward points if it helps.

[Former Member]

Hi

open sql statements: consists of set of abap statements that perform operations on central database in sap.

insert,delete,select.modify,update,open cursor etc.

native sql staements:it allows you to use database specific sql staements in abap program.

we can use database tables that are not administrated by the abap dictionary.

EXCS is the native st in abap.

we always use OPEN SQL STAEMENTS because they r database independent where as native sql st are database dependent.

Open SQL allows you to access all database tables known to the SAP system, regardless of the database manufacturer. Sometimes, however, we may want to use database-specific SQL statements called Native SQL in your ABAP/4 program.

To avoid incompatibilities between different database tables and also to make ABAP/4 programs independent of the database system in use, SAP has created a set of separate SQL statements called Open SQL. Open SQL contains a subset of standard SQL statements as well as some enhancements which are specific to SAP.

A database interface translates SAP's Open SQL statements into SQL commands specific to the database in use. Native SQL statements access the database directly

[Former Member]

Hi All,

I would like to know how can I update a table in MS SQL database.

TRY.

EXEC SQL.

UPDATE sap_sync

SET (orders = :wa-c_orders,

travel = :wa-c_travel)

ENDEXEC.

CATCH cx_sy_native_sql_error INTO oref .

ENDTRY.

Actually I'm getting an exception with this command.

Thanks in advance

Alexis