sql primary key autoincrement

Add a table field ALTER TABLE table1 add transactor varchar (a) not Null; ALTER TABLE table1 add ID int unsigned not Null auto_increment primary key Modify the field type of a table and specify null or Non-empty ALTER TABLE name change field Name field name FieldSize field type [Allow Non-null]; ALTER TABLE name modify field Name field type [Allow Non-null]; ALTER TABLE name modify field Name field ty

at the IAM information, as follows:Slot 0 = (1:79) Slot 1 = (1:89) Slot 2 = (1:90)Slot 3 = (1:93) Slot 4 = (1:94) Slot 5 = (1:109)Slot 6 = (1:110) Slot 7 = (1:114)Iam:extent Alloc Status Slot 1 @0x592ec0c2(1:0)-(1:176) = Not allocated(1:184)-(1:192) = Allocated(1:200)-(1:376) = Not allocatedThe Highlight section indicates the partition information for IAM, and the first data page pointer points to the page. This is consistent with the first_page values we have queried . An IAM page corresponds

--CREATE database Db_std_mgr_sys; UseDb_std_mgr_sys;Create TableStudent (std_idbigint not NULLAuto_increment,std_namevarchar(Ten) not NULL default "', Std_codevarchar( -) not NULL default "'Comment'study number, the value is unique', Std_sexvarchar(8) not NULL default "', Std_phonevarchar( -) not NULL default "', school_idbigint not NULL default -1Comment'Your School ID', grade_idBIGINT not NULL default -1Comment'your Grade ID', cls_idbigint not NULL default -1Comment'Your class ID',

After inserting a record, you want to immediately obtain the primary key return value in the data table. This primary key is automatically generated. In fact, there are many implementation methods, such as performing another query and obtaining it. Alternatively, you can obtain the maximum value before inserting data,

After inserting a record, you want to immediately obtain the primary key return value in the data table. This primary key is automatically generated. In fact, there are many implementation methods, such as performing another query and obtaining it. You can also extract the maximum value before inserting data and add on

Tags: else strong dev sql col span word round intInsert fails when data is inserted, assuming that the value corresponding to the primary key already exists! This is the primary key violation.When the primary

Sets whether to use the Getgenereatedkeys method of JDBC to get the primary key and assign a value to the domain model property of the Keyproperty setting. MySQL and SQL Server execute auto-generated key field, so when the database is set to self-grow primary

SQL statement query the table name/column name/primary key/automatic Growth Value in the database---- Query tables created by users in the database---- Jsj01 indicates the database name.Select name tablename from jsj01.. sysobjects where type = 'U' and name not in ('dtproperties ')-- Query the field information in the table--- Docs: Table Name---- Select * from s

1. ORACLE uses SELECT seq_id.nextval from dual (seq_id the sequence name corresponding to the primary key)2, DB2 use VALUES identity_val_local ()3. MYSQL using SELECT last_insert_id ()4. SQL Server uses SELECT scope_identity ()5. DERBY use VALUES identity_val_local ()6. HSQLDB using the call IDENTITY ()7. SYBASE uses SELECT @ @IDENTITY ()8, DB2_MF use SELECT iden

Do not specify an order by in SQL, sort by the primary key? The answer is not necessarily. As an example: Query Attendanceemprank table, primary key is Attendanceemployeerankid, and is clustered index Execute the following statement and find that the first sentence does

Tags: style blog color ar div log sp on ad--Delete primary KeyDeclare @Pk VarChar( -);Select @Pk=Name fromsysobjectswhereParent_obj=object_id('Swtoolsupdaterecord') andXtype='PK';if @Pk is not NULLexec('Alter table Swtoolsupdaterecord Drop'+ @Pk)--Reset PRIMARY KeyALTER TableSwtoolsupdaterecordADD CONSTRAINTPknamePRIMARY KEY(ID)--view current

Create a role tableCREATE TABLE Nbctxp. Tbl_nbc_nonbankrole (ID BIGINT not NULL,ROLENAME VARCHAR (50),Createtime TIMESTAMP,UpdateTime TIMESTAMP,CONSTRAINT p_id PRIMARY KEY (ID));CREATE INDEX SQL150130091455900 on NBCTXP. Tbl_nbc_nonbankrole (ID);Let the primary key increment by 1Alter table Nbctxp. Tbl_nbc_nonbankrole

Oracle primary key deletion, joint primary key creation, oracle primary key1. Delete the primary key alter table tablename drop PRIMARY_KEY execute the preceding

Label:Sometimes to get the table primary key field, although the system from the stored procedure can be obtained, but for familiar with the system table, it is easy to write yourself.2 Declare @table_name varchar 3 Set @table_name = ' Table_pqs ' 4 --1, according to system stored procedure 5 Execute Sp_pkeys @table_name 6 7 --2, obtained 8 Declare @objectid int 9 Set @

Recently, I have used the operation of SQL Server database to do something. Well, really long time did not see, to this database is unfamiliar to the pole, even the simplest how to set an ID primary key, let it with the insertion of data, automatic growth ID value settings are forgotten, online check a bit, many people say the use of code, like I want to be diffe

SELECT primary key Column Id=b.rkey, primary key Column name = (SELECT name from syscolumns WHERE Colid=b.rkey and Id=b.rkeyid), FOREIGN key table Id=b.fkeyid, foreign key table name =object_name (B.fkeyid), Foreign

Label:The following code has been found on the Internet:DECLARE @Pk varchar (100);Select @Pk =name from sysobjects where parent_obj=object_id (' table name ') and xtype= ' Pk ';If @Pk is not nullBeginEXEC (' Alter table name Drop ' + @Pk)--Delete the primary keyEndThe point here is that the table Sysobjects,sysobjects table is a system table, each object created in the database (constraints, defaults, logs, rules, stored procedures, etc.) in the table

This morning, I learned about the use of primary and foreign keys in SQL Server and how to establish the connection between primary key and foreign key.In the afternoon, I learned how to apply the subquery inside SQL Server, and also practiced the use of functions (String fu