sql create table with foreign key

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

Create Procedure Genforeignkey @ Tablename Varchar ( 200 ) -- Name of the table in the foreign key database to be added As Declare @ Cur Cursor Declare @ FK Varchar ( 100 ) Declare @ Execsql Varchar ( 8000 ) Begin Declare @

Modify the table structure to add foreign key constraints. The default foreign key name to modify the table structure to add foreign key con

is not necessarily a primary key, but must be a unique index. primary KEY constraints and uniqueness constraints are unique indexes. FOREIGN KEY Constraint SQL Server 2008Other versions A foreign

\ ' database name \ ', \ ' autoshrink\ ', \ ' true\ '\\\ ' Add field general functionSub AddColumn (Tablename,columnname,columntype)Conn.execute (\ "Alter Table \" tablename\ "ADD \" columnname\ "\" columntype\ "\")End Sub\\\ ' Change field general functionSub Modcolumn (Tablename,columnname,columntype)Conn.execute (\ "Alter Table \" tablename\ "alter Column \" columnname\ "\" columntype\ "\")End Sub\\\ '

1. CREATE TABLE test6: foreign key named TEST3_FKMysql> CREATE TABLE Test6 (ID int,Test_name varchar (32),-Constraint TEST3_FK foreign key (

, select Yes in the pop-up window, and then add three tables, then you can see the relationship between the three tables.3.2 Setting foreign keys with SQL statements3.2.1 Select Database->sqltest, and then select New Query. Notice the box in the upper left corner to select Sqltest, if not, select it manually.3.2.2 Enter the following code in the new query interface:--This is the comment information in

determines the record of another table, which is used to maintain data consistency. For example, a field in a table is the primary key of table B, so he can be a foreign key to table A

/// /// Query Method/// /// /// Public dataset query (string tabnames, string columnname){Using (oraclehelper orahp = new oraclehelper ()){String [] tabs = tabnames. Split (',');Dataset DATA = new dataset ();Orahp. open ();For (INT I = 0; I {String tabtemp = tabs [I];String SQL = "select nvl (v. foreign key table, '"+

(SQL The data distribution and subscription mechanism of the server allows us to replicate the data between libraries, and the autogrow field may cause a primary key conflict when the data is merged. Imagine that the order table in one database replicates the number of order tables in another library According to the library, OrderID should not automatically gro

. In addition, when we need to replicate data between multiple databases (SQL Server's data distribution, subscription mechanism allows us to replicate data between libraries), auto-growing fields can cause primary key conflicts when data is merged. When you imagine that an order table in a database replicates a database to an OrderID in another library, should

specific principle here is not clear, the above is only speculation, hereby recordedIf you find a reason to update!Update:Https://stackoverflow.com/questions/22013511/mysql-error-1215-hy000-cannot-add-foreign-key-constraintThat is to say, my above guess is correct!Take a look at the unique test:Transferred from: http://www.cnblogs.com/Andy963/p/7634537.htmlThe last thing to note is that the

ORACLE Database Table creation, auto-incrementing primary key, foreign key syntax explanation, oracle primary key1. Create a table structure: Drop table base_list;

\ ' database name \ ', \ ' autoshrink\ ', \ ' true\ '\\\ ' Add field general functionSub AddColumn (Tablename,columnname,columntype)Conn.execute (\ "Alter Table \" tablename\ "ADD \" columnname\ "\" columntype\ "\")End Sub\\\ ' Change field general functionSub Modcolumn (Tablename,columnname,columntype)Conn.execute (\ "Alter Table \" tablename\ "alter Column \" columnname\ "\" columntype\ "\")End Sub\\\ '

Create a table:Create table [table name]([Automatic number field] int IDENTITY (1, 1) primary key,[Field 1] nVarChar (50) default \ 'default value \ 'null,[Field 2] ntext null,[Field 3] datetime,[Field 4] money null,[Field 5] int default 0,[Field 6] Decimal (12, 4) default 0,[Field 7] image null,) Delete table:Drop

Tags: style blog ar color sp for on data divThe role of the primary and foreign keys of sql:Foreign key value rule: A null value or a reference primary key value.(1) When a non-null value is inserted, it cannot be inserted if the value is not in the primary key table.(2) Whe

TABLE Teacher ( te_id int PRIMARY key auto_increment,--primary key self-increment, non-null unique Te_name varchar () NOT NULL,--non-null Te_subject varchar () NOT NULL,--non-null Te_yn varchar Check (te_yn= ' y ' or te_yn= ' n ')--limit only to ' Y ' or ' n ' ) Teacher Class Association table (Cla_teacher) CT_ID (ass

Simple tutorial on SQL statements in linux --- primary key, foreign key, and SQL Primary Key)Each item in is a unique value in the table. In other words, it is used to uniquely identify

withno_logDBCCshrinkdatabase (database name)execsp_dboption \'database name \', \'autoshrink\', \'true\' \\\'Add field General function Sub AddColumn (tablename,columnname,columntype) Conn.execute (\ "Alter Table \" tablename\ "add \" columnname\ "\" columntype\ "\") End Sub \\\'Change the field general function Sub Modcolumn (tablename,columnname,columntype) Conn.Execute(\"Alter Table\"TableName\"Alter C