update primary key sql

SQL primary key constraints and foreign key constraints, SQL primary key constraintsPrimary key constraint

) values (1, 3), (1, 7) on duplicate key update c = values (C ); After the execution, the value of C will change to 7 (the second repeat with the first repeat, and C will take the repeat value 7 directly ).Note: On duplicate key update is only a special MySQL syntax, not a standard

Insert on Dumplicate Update when the primary key is the same update, the contents of the update change to 1 Multiple contents of update are separated by commas ... And notmysql> insert INTO ' 200702 ' (' Domain ', ' 2nd_domain '

columns, change the column's order, index name, aggregation options, or fill factor for the PRIMARY key constraint. However, you cannot change the length of the column defined using the PRIMARY KEY constraint. Attention:To modify a PRIMARY

');View field information for a tableDESC table name; Show columns from table name;View all information for a tableShow create table table name;Add a PRIMARY KEY constraintALTER TABLE name add constraint primary Key name (Shape: Pk_ table name) primary

Tags: style http color io strong for AR artAdd a table fieldALTER TABLE table1 add transactor varchar (ten) not Null;ALTER TABLE table1 add ID int unsigned not Null auto_increment primary keyModify the field type of a table and specify empty or non-emptyALTER TABLE name change field Name field Name field type [whether non-null allowed];ALTER TABLE name modify field Name field type [allow non-null];ALTER TABLE name modify field Name field type [allow n

SQL: the primary key of a data table is of the varchar type and does not increase itself. how can I insert a primary key when inserting data? SQL: the primary

Tags: primary key first break range Ror add comment art DropSQL PRIMARY KEY ConstraintThe PRIMARY KEY constraint uniquely identifies each record in a database table. The primary

further explained: We need to modify the following SC table foreign key Declaration, add the name of the foreign key constraint, to facilitate our subsequent masking and recovery of foreign KEY constraints: create table SC (s# integer , C # integer , Scor E integer , constraint sidfk foreign key (

: We need to change the following SC table foreign key Declaration, add the name of the foreign key constraint, so that we might block and restore foreign KEY constraints: create table SC (s# integer , C # integer , Score Span class= "Hljs-keyword" >integer , constraint sidfk foreign key (s#) referen

Tags: style http color io strong for AR Art Div www.169it.comAdd a table fieldALTER TABLE table1 add transactor varchar (ten) not Null;ALTER TABLE table1 add ID int unsigned not Null auto_increment primary keyModify the field type of a table and specify empty or non-emptyALTER TABLE name change field Name field Name field type [whether non-null allowed];ALTER TABLE name modify field Name field t

The last one we said about self-draining if the primary key is 0, here I figure out why, cause this is because the initial value is set in SQL for the self-row:　　From here you can see that the two variables, one is the increment of the initial value, one is incremental, here is 1, so when the setting of self-increment will be that field of the original existence

SQL: The primary key of a data table is a varchar type, does not increment, how to insert a primary key when inserting data Reply content: SQL: The primary

At the beginning of this demand, in the online search, found all said no, you have to delete the primary key column and then re-add or create a temporary table before the data, in fact, can be directly modified in MySQL.Modify the ID field to self-increment the primary key:ALTER TABLE ' Test ' change ' ID ' ' id ' int (one) UNSIGNED not NULL auto_increment, add

Tags: mysqlFirst describe the cause of this problem, suppose there is a table, which holds the trade orders, each order has a unique ID, the last update time, and the data, the details are as follows:+-------+----------+------+-----+---------------------+-------+ |field|type |Null|Key|Default |extra| +-------+----------+------+-----+---------------------+-------+ |uid|int (11) |NO|PRI|0 | | |time|datetime|n

Create PROCEDURE pro_test (@userName NVARCHAR ( -) ) as--Select* from[dbo]. [Table_2]--SELECT *From [dbo]. [Student] Beginbegin TRAN DECLARE @tempTable TABLE (tempid uniqueidentifier) DECLARE @tempId uniqueidentifier INSERT into tabl E_2 (UserName) OUTPUT Inserted.userid into @tempTable VALUES (@userName)--insert data into the first table SELECT @tempId=tempid from @tempTable--assign a value to the middle variable INSERT into dbo. Student (Stuname, Stuage, Stusex,stucode) VALUES ('Zhansan',Ten,'

Data | database-building a database Create DATABASE test; Go --Establish table customers CREATE TABLE Customers ( ID int identity (1,1) not NULL, Name varchar (15), Age int, Primary KEY (ID) ); Go --Establish the table orders CREATE TABLE Orders ( ID int identity (1,1) not NULL, Order_number varchar (15), Price, customer_id int, Primary