Points: 1004558 More actions In your case, it is better to have a unique constraint enabled rather than having a primary key (Since it is nvarchar(255). Ummmm... not necessarily true. A non-clustered PK would work just fine here. -...
In MySQL and SQL Server, adding a foreign key to multiple columns requires that the referenced columns have aUNIQUE constraintor COMPOSITE PRIMARY KEY. For example, we alter theDepartmenttable to add a UNIQUE CONSTRAINT on theidandnamecolumns: ALTER TABLE Department ADD CONSTRAINT uq_department UNI...
LockPagesInMainMemory = 0 my.cnf: [mysqld] query_cache_size = 0 query_cache_type = OFF sql_mode = TRADITIONAL bind-address = 0.0.0.0 ndb-connectstring = 127.0.0.1 ndb-cluster-connection-pool = 1 character-set-server = utf8 ...
Used in an index. Used in a CHECK, FOREIGN KEY, UNIQUE, or PRIMARY KEY constraint. Associated with a DEFAULT definition, or bound to a default object. Bound to a rule. Registered for full-text support. Used as a full-text key for a table.For information about adding and deleting ...
In my environment I have a table with around 5 million records and two indexes. I want to know what will be the effect on the existing indexes, if i add a new column to this table i.e. whether indexes are dropped and created again or updated somehow or there is no effect at al...
In this DocumentPurposeTroubleshooting StepsWhat causes the "java.sql.SQLException: ORA-00001: unique constraint (DB.PK) violated" issue? Content Management Example (CM_NODE, NODE_ID, SEQUENCER, SEQUENCE_NAME, NODE_ID_SEQUENCE)How does a Primary Key value get out of sync?How to resolve the ...
Description: MySQL returns wrong warning-message when trying to add FOREIGN KEY CONSTRAINT between mismatched-datatype columns. How to repeat: mysql80 117> CREATE TABLE t1 (num int signed not null, PRIMARY KEY(num)) /* num is SIGNED int */; Query OK, 0 rows affected (0.06 sec) mysql80...
I'm trying to play around with the mixin in order to add some features, in this case anis_latesttag. For sake of performance, I strongly prefer it to be loaded with the object and avoid using a completely separate query for all versioned rows. ...
[KeyID] [bigint] IDENTITY(1,1) NOT NULL, [UserName] [dbo].[bVPUserName] NOT NULL, [Sequence] [int] NOT NULL, [Title] [dbo].[bDesc] NOT NULL, [Signature] [dbo].[bFormattedNotes] NULL, [IsDefault] [dbo].[bYN] NULL CONSTRAINT [DF_vPMEmailSignature_IsDefault] DEFAULT ('N') ...
ERROR 1452: Cannot add or update a child row: a foreign key constraint fails (`journals`.<result 2 when explaining filename '#sql-b5c_3') But when not using NOT NULL on creation on Column is works fine to add a foreign key ??? Can someone please explain this to me ? because ...