Difference between revisions of "Creating tables in SQL Server"
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Foreign constraint prevents invalid data from being entered into the foreign key column. The foreign key value must be one of the values contained in the table it references. | Foreign constraint prevents invalid data from being entered into the foreign key column. The foreign key value must be one of the values contained in the table it references. | ||
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| + | '''Creating a table using sql'''<br> | ||
| + | |||
| + | Use [Sample]<br> | ||
| + | Create Table tblGender<br> | ||
| + | {<br> | ||
| + | ID int NOT NULL Primary Key,<br> | ||
| + | Gender nvarchar(50) NOT NULL,<br> | ||
| + | }<br> | ||
| + | |||
| + | Check the gui way of adding a foreign key constraint <br> | ||
| + | |||
| + | Difference between nvarchar and varchar :<br> | ||
| + | '''varchar:''' Variable-length, non-Unicode character data. The database collation determines which code page the data is stored using.<br> | ||
| + | '''nvarchar:''' Variable-length Unicode character data. Dependent on the database collation for comparisons.<br> | ||
Latest revision as of 01:11, 3 September 2015
Alter table table1 add constraint <name of constraint>
FOREIGN KEY (<column>) references table2 (<primary key column>)
Foreign constraint prevents invalid data from being entered into the foreign key column. The foreign key value must be one of the values contained in the table it references.
Creating a table using sql
Use [Sample]
Create Table tblGender
{
ID int NOT NULL Primary Key,
Gender nvarchar(50) NOT NULL,
}
Check the gui way of adding a foreign key constraint
Difference between nvarchar and varchar :
varchar: Variable-length, non-Unicode character data. The database collation determines which code page the data is stored using.
nvarchar: Variable-length Unicode character data. Dependent on the database collation for comparisons.
