Once I migrated an MSAccess DB, I found the following: 1) PRIMARY KEY definitions are converted to UNIQUE INDEX 2) PRIMARY KEY are created (with the name 'PRIMARY') for any AUTO INCREMENT columns in a table (instead of using the pre-defined PRIMARY KEY) 3) FOREIGN KEYS are ...
问题现象使用如下的 sql 语句创建自关联外键表:drop table self_f_key;create table self_f_key(t1 number primary key not null..., t2 number);create index i_s_1 on self_f_key(t2);alter ...
SQL Server / Oracle / MS Access: CREATETABLEOrders ( OrderID intNOTNULLPRIMARYKEY, OrderNumber intNOTNULL, PersonID intFOREIGNKEYREFERENCESPersons(PersonID) ); To allow naming of aFOREIGN KEYconstraint, and for defining aFOREIGN KEYconstraint on multiple columns, use the following SQL syntax: ...
Can a [non primary key] be referenced as [foriegn key] in other table? Can a uniqueidentifier have a default value? can I access function on remote server through linked server? Can i call a stored procedure in view?. Can I configure FILESTREAM to use file share? Can I delete NT SERVI...
如果CONSTRAINT identifier和FOREIGN KEY identifier语句都没有指定名称,则会自动生成一个名称,例如fk_1、fk_2、fk_3等。 外键名称必须在当前表中唯一,否则创建时会报错ERROR 1826: Duplicate foreign key constraint name 'fk'。 限制 创建外键时需要满足以下条件: ...
24-SQL FOREIGN KEY 约束 一个表中的FOREIGN KEY(外键) 指向另一个表中的PRIMARY KEY SQL FOREING KEY Constraint on CREATE TABLE SQL FOERIGN KEY Constraint on ALTER TABLE "Orders"表中的“Id_P”列指向"Persons"表中的“Id_P”列 “Persons”表中的“Id_P”列是“Persons”表中的PRIMARY KEY ...
You then try to TRUNCATE table1 which fails with the "is being referenced by a FOREIGN KEY constraint" error, which is expected. You can see from this that the sp_msforeachtable statement isn't doing what you wanted it to do since it's only impacting operations on...
also permits fast access to data when the primary key is used in queries. If a primary key constraint is defined on more than one column, values can be duplicated within one column, but each combination of values from all the columns in the primary key constraint definition must be unique....
"[Microsoft][ODBC Microsoft Access Driver]General error Unable to open registry key Temporary (volatile) Ace DSN for process" "Attachment" data type in SQL Server 2012 "Cannot define field more than once" message "Could not update, currently locked by another session on this machine" error "...
When migrating a Microsoft Access 2003 database to MySQL, using the latest MySQL Migration Toolkit (version 1.0.10 beta). I get satisfactory results, except for the foreign keys. Only one foreign key per table is created. In the ‘Manual editing’ step of the tool, selecting the ‘Show ...