Check table exist or not before create it in Oracle
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Trying to check is table exist before create in Oracle. Search for most of the post from Stackoverflow and others too. Find some query but it didn't work for me.
IF((SELECT count(*) FROM dba_tables where table_name = 'EMPLOYEE') <= 0) THEN create table EMPLOYEE ( ID NUMBER(3), NAME VARCHAR2(30) NOT NULL ) END IF;
Which gives me error
Error: ORA-00900: invalid SQL statement SQLState: 42000 ErrorCode: 900 Position: 1
I search for the syntax for
IF condition, I think which is also write.
Please suggest me....
As Rene also commented, it's quite uncommon to check first and then create the table. If you want to have a running code according to your method, this will be:
declare nCount NUMBER; v_sql LONG; begin SELECT count(*) into nCount FROM dba_tables where table_name = 'EMPLOYEE'; IF(nCount <= 0) THEN v_sql:=' create table EMPLOYEE ( ID NUMBER(3), NAME VARCHAR2(30) NOT NULL )'; execute immediate v_sql; END IF; end;
But I'd rather go catch on the Exception, saves you some unnecessary lines of code:
declare v_sql LONG; begin v_sql:='create table EMPLOYEE ( ID NUMBER(3), NAME VARCHAR2(30) NOT NULL )'; execute immediate v_sql; EXCEPTION WHEN OTHERS THEN IF SQLCODE = -955 THEN NULL; -- suppresses ORA-00955 exception ELSE RAISE; END IF; END; /
CREATE TABLE IF NOT EXISTS on Oracle database, You can query USER_TABLES (or ALL_TABLES or DBA_TABLES depending on whether you are creating objects owned by other users and your privileges in the database) to check to see whether the table already exists. Trying to check is table exist before create in Oracle. Search for most of the post from Stackoverflow and others too. Find some query but it didn't work for me. IF((SELECT count(*) FROM dba_tables where table_name = 'EMPLOYEE') <= 0) THEN create table EMPLOYEE ( ID NUMBER(3), NAME VARCHAR2(30) NOT NULL ) END IF;
I know this topic is a bit old, but I think I did something that may be useful for someone, so I'm posting it.
I compiled suggestions from this thread's answers into a procedure:
CREATE OR REPLACE PROCEDURE create_table_if_doesnt_exist( p_table_name VARCHAR2, create_table_query VARCHAR2 ) AUTHID CURRENT_USER IS n NUMBER; BEGIN SELECT COUNT(*) INTO n FROM user_tables WHERE table_name = UPPER(p_table_name); IF (n = 0) THEN EXECUTE IMMEDIATE create_table_query; END IF; END;
You can then use it in a following way:
call create_table_if_doesnt_exist('my_table', 'CREATE TABLE my_table ( id NUMBER(19) NOT NULL PRIMARY KEY, text VARCHAR2(4000), modified_time TIMESTAMP )' );
I know that it's kinda redundant to pass table name twice, but I think that's the easiest here.
Hope somebody finds above useful :-).
create table if not exists?, EXECUTE IMMEDIATE 'create table NO_TABLE_JOHN ( ID or test database to make sure things work well before the production release. unlike mssql where you have to inquire first, it's not essential in Oracle. perhaps I'm not understanding the need however. cursor tab_found(p_tab) is. select table_name from all_tables where table_name=p_tab;
SET SERVEROUTPUT ON DECLARE v_emp int:=0; BEGIN SELECT count(*) into v_emp FROM dba_tables where table_name = 'EMPLOYEE'; if v_emp<=0 then EXECUTE IMMEDIATE 'create table EMPLOYEE ( ID NUMBER(3), NAME VARCHAR2(30) NOT NULL)'; end if; END;
Check that table exists, You can also check the data dictionary to see if a table exists: SQL> select table_name from user_tables where table_name='MYTABLE'; Another way to test if a table exists is to try to drop the table and catch the exception if it does not exist. We can use OBJECT_ID() function like below to check if a tblTest Table exists in the current database. IF OBJECT_ID(N'dbo.tblTest', N'U') IS NOT NULL BEGIN PRINT 'Table Exists' END Specifying the Database Name and Schema Name parts for the Table Name is optional.
declare n number(10); begin select count(*) into n from tab where tname='TEST'; if (n = 0) then execute immediate 'create table TEST ( ID NUMBER(3), NAME VARCHAR2 (30) NOT NULL)'; end if; end;
how to check if table exists, Can anyone please tell me if it is possible to check whether a table exists >From: "Anastasia Purnomo via oracle-db-l" <oracle-db-l@OpenITx.com> Note that this screams of a lack of upfront analysis - why not create the table ahead of time If this is part of the installation, you should know what objects exist at any point in the process so you shouldn’t need to check whether a table already exists. Oracle CREATE TABLE IF NOT EXISTS Equivalent. To check if a table exists before creating it, you’ll need to write a PL/SQL block. There are a few ways you can check:
My solution is just compilation of best ideas in thread, with a little improvement. I use both dedicated procedure (@Tomasz Borowiec) to facilitate reuse, and exception handling (@Tobias Twardon) to reduce code and to get rid of redundant table name in procedure.
DECLARE PROCEDURE create_table_if_doesnt_exist( p_create_table_query VARCHAR2 ) IS BEGIN EXECUTE IMMEDIATE create_table_query; EXCEPTION WHEN OTHERS THEN -- suppresses "name is already being used" exception IF SQLCODE = -955 THEN NULL; END IF; END; BEGIN create_table_if_doesnt_exist(' CREATE TABLE "MY_TABLE" ( "ID" NUMBER(19) NOT NULL PRIMARY KEY, "TEXT" VARCHAR2(4000), "MOD_TIME" TIMESTAMP DEFAULT CURRENT_TIMESTAMP ) '); END; /
How to check if a table exists in an Oracle SQL Script Solutions , IF NOT EXISTS (SELECT 1 FROM INFORMATION_SCHEMA. PortlerPaul - If I try and CREATE a table that already exists I get a name is EMP_WarningType_TRG BEFORE INSERT ON EMP_WarningType FOR EACH The NOT EXISTS operator returns true if the subquery returns no row. Otherwise, it returns false. Note that the NOT EXISTS operator returns false if the subquery returns any rows with a NULL value. Oracle NOT EXISTS examples. See the following customers and orders tables in the sample database: The following statement finds all customers who
Oracle: If Table Exists, To avoid the overhead of checking if the table exists twice or not” and to avoid the exception which is raised to the caller due to the DROP If you run following code you do not have to check if table exists and in case of errors (table is locked with now wait or any other you will know about it) begin for c1 in (select owner,table_name from dba_tables where table_name='MY_TABLE') loop execute immediate 'drop table '||c1.owner||'.'||c1.table_name||''; end loop; end;
how To check table exists in Oracle?.. - Oracle Database, Oracle Database Forums on Bytes. Hello Everyone I m Creating one procedure in that i want to check for existence of table i want to something like this. if (v=1) then; <table exists>; else; <table does not exist>; end if;. or. Introduction to the Oracle EXISTS operator. The Oracle EXISTS operator is a Boolean operator that returns either true or false. The EXISTS operator is often used with a subquery to test for the existence of rows: SELECT * FROM table_name WHERE EXISTS (subquery); The EXISTS operator returns true if the subquery returns any rows, otherwise, it
SQL CREATE TABLE Syntax and Examples, Oracle CREATE TABLE IF NOT To check if a table exists before creating it,
- You need to put that into a PL/SQL block.
- It's quite common in Oracle scripts to just try and create the table and then catch the exception if the table already exists.
- You want to check if the table exists in a specific schema.
- Looks good, but you appear to have named your parameter 'p_create_table_query', but have called it using the name 'create_table_query', meaning this won't compile.