2024 Create unique index case when oracle

Create unique index case when oracle

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WebApr 30, 2005 · unique index with null values Hello Tom,I have this situation: With a table like create table test (id number not null,name varchar2(10) not null,source_id … WebFeb 1, 2000 · SQL> insert into registrations values (11, 'PLS' ,date '2000-09-11' ,NULL); 1 row created. SQL> SQL> create unique index oau_reg on registrations 2 ( case course when 'OAU' then attendee else null end 3 , case course when 'OAU' then course else null end ); Index created.

create unique index with case ... when statement : Create Index « Index ...

WebExample #1. Single column UNIQUE constraint using CREATE statement. In this case we are going to add unique constraint to a column in a table while creating the table. In the example a table school will be created with school_id column being the column with UNIQUE constraint using the create statement. WebOct 24, 2012 · To do this, you can use a unique function-based index: CREATE UNIQUE INDEX func_based_index ON the_table (CASE WHEN unique_value IS NOT NULL AND unique_group_id IS NOT NULL THEN UNIQUE_VALUE ',' UNIQUE_GROUP_ID END); you can use the nvl function to avoid nulls and place a different value instead , the … new movies on dvd 2015

How to create unique index on fields with possible null values (Oracle …

WebThe syntax for creating Unique Index is as follows: SQL. CREATE UNIQUE INDEX index_name. ON table_name(column1, column2)... Here, index_name – It is the name … WebDec 3, 2009 · You will be able to store only one instance of NULLs however (no two sets of same columns will be allowed unless all columns are NULL) : SQL> CREATE TABLE t (id1 NUMBER, id2 NUMBER); Table created SQL> ALTER TABLE t ADD CONSTRAINT u_t UNIQUE (id1, id2); Table altered SQL> INSERT INTO t VALUES (1, NULL); 1 row … WebUse the CREATE INDEX statement to create an index on: One or more columns of a table, a partitioned table, an index-organized table, or a cluster. One or more scalar typed … introducing solids to baby australia

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unique index with null values - Ask TOM - Oracle

WebHi Guys, Is it possible to create an unique constraint which is case insensitive I mean if there is a unique constraint on col name This site is currently read-only as we are migrating to Oracle Forums for an improved community experience. WebHere is the execution plan: To encounter this, Oracle introduced function-based indexes. A function-based index calculates the result of a function that involves one or more columns and stores that result in the index. The following shows the syntax of creating a function-based index: CREATE INDEX index_name ON table_name (expression) new movies on disney plus for kidsWebIf it's guaranteed that only one of a_key, b_key, and c_key will not be null, (with for example a check constraint) then you could create your unique index as: create unique index key_tab_ix on key_tab (coalesce(a_key,b_key,c_key)); I would change your select statement to the following: introducing solids to baby with reflux

"WebApr 4, 2013 · 7. Assuming your table is called person, and the first and last name columns are called first_name and last_name, add this unique constraint: ALTER TABLE person ADD CONSTRAINT person_name_unique UNIQUE (LOWER (first_name),LOWER (last_name)); Let me know if I understood your question correctly and made the correct … " - Create unique index case when oracle

Create unique index case when oracle

How to create unique index on fields with possible null values (Oracle …

WebPerhaps a function-based index will do what you want. For example: CREATE UNIQUE INDEX moo_unique ON moo ( NVL2 (secunda, prima, NULL) , NVL2 (secunda, tertia, NULL) ); The effect of the index above is to have a unique index on (prima, tertia) that only applies to rows where secunda is not NULL. WebHow do I create a clustered index in SQL? On the Table Designer menu, click Indexes/Keys. In the Indexes/Keys dialog box, click Add. Select the new index in the Selected Primary/Unique Key or Index text box. In the grid, select Create as Clustered, and choose Yes from the drop-down list to the right of the property.

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WebThe CREATE UNIQUE INDEX command creates a unique index on a table (no duplicate values allowed) Indexes are used to retrieve data from the database very fast. The users cannot see the indexes, they are just used to speed up searches/queries. The following SQL creates an index named "uidx_pid" on the "PersonID" column in the "Persons" table: WebAug 20, 2012 · An interesting question was posed on the Oracle-L list a few weeks back; a member was having difficulty getting a constraint created using an existing non-unique index, as Oracle would consistently consume all of the TEMP space and cause the process to terminate for lack of resources.

WebNov 10, 2010 · I know how to create a deferrable unique index: alter table LIST_ITEM add constraint LIST_ITEM_ENTRY_NO_UNIQ unique (LIST_KEY,ENTRY_NO) deferrable initially deferred; Knowing these two things, I tried this: alter table LIST_ITEM add constraint LIST_ITEM_ENTRY_NO_UNIQ unique (case STATUS when 'cancel' then null else … WebApr 30, 2005 · unique index with null values Hello Tom,I have this situation: With a table like create table test (id number not null,name varchar2(10) not null,source_id number);(actually the real tables have more columns, but for this question these are enough)and with this rowsinsert into test values(1,'name1',1);

WebOct 6, 2024 · To tell Oracle create function based index on your table, use the below syntax: CREATE [UNIQUE] INDEX index_name ON table_name (function1, function2, …

Web11. This occurs when you try to execute a CREATE UNIQUE INDEX statement on one or more columns that contain duplicate values. Two ways to resolve (that I know of): Remove the UNIQUE keyword from your CREATE UNIQUE INDEX statement and rerun the command (i.e. if the values need not be unique). If they must be unique, delete the … introducing someone in emailWebJun 18, 2024 · How to create an index on CASE expression in Oracle. DECLARE MGMT_ID NUMBER; SSHKEY_MGMT_ID NUMBER; BEGIN SELECT ID INTO … new movies on dvd releaseWebAug 20, 2024 · Or you can include a using index clause in your add constraint. ALTER TABLE user_account ADD CONSTRAINT uc_user_name UNIQUE (user_name) USING … new movies on dvd family videoWebJan 9, 2024 · SQL> -- Function-based index - unique when active = Y SQL> create unique index test_uf1 2 on test 3 (case when active = 'Y' 4 then id 5 else null 6 end); Index created. In pre-11g Oracle [i.e. no virtual columns – more on this in a later post] , you cannot add a similar conditional unique constraint. introducing solids to babiesWebJan 10, 2011 · CREATE UNIQUE INDEX u_a_key ON a( (CASE WHEN z = 'N' THEN x ELSE null END), (CASE WHEN z = 'N' THEN y ELSE null END) ); If z is not 'N', both CASE statements evaluate to NULL and Oracle doesn't have to store the x & y values in the index structure (making the index smaller). If z is 'N', the x & y values are both stored in the … introducing someone over email exampleWebAn index can be unique or non-unique. A unique index ensures that no two rows of a table have duplicate values in the indexed column (or columns). A non-unique index … introducing someone new to the teamWebAnswer: Using function-based indexes (FBI) you can create an index on any built-in function, including a CASE expression. Here we use CASE within the create index … new movies on einthusan