Six types of constraints can be placed when creating a table: NOT NULL Constraint: Ensures that a column cannot have NULL value.DEFAULT Constraint: Provides a default value for a column when none is specified.UNIQUE Constraint: Ensures that all values in a column are different.CHECK...
Note:We must provide data types for each column while creating a table. To learn more, visitSQL Data Types. CREATE TABLE IF NOT EXISTS If we try to create a table that already exists, we get an error message'Error: table already exists'. To fix this issue, we can add the optionalIF...
For an example, see Create a partitioned table. Ordered clustered columnstore index option Clustered columnstore index (CCI) is the default for creating tables in Azure Synapse Analytics. Data in a CCI is not sorted before being compressed into columnstore segments. When creating a CCI with ORDER...
and update the values when any other columns on which the computed column depends are updated. Marking a computed column as PERSISTED lets you create an index on a computed column that is deterministic, but not precise. For more information, seeCreating Indexes on Computed Columns...
_table_name [ ( ref_column [ ,... n ] ) ] [ ON DELETE { NO ACTION | CASCADE | SET NULL | SET DEFAULT } ] [ ON UPDATE { NO ACTION | CASCADE | SET NULL | SET DEFAULT } ] [ NOT FOR REPLICATION ] | CHECK [ NOT FOR REPLICATION ] ( logical_expression ) } <table_index> ...
_table_name [ ( ref_column [ ,... n ] ) ] [ ON DELETE { NO ACTION | CASCADE | SET NULL | SET DEFAULT } ] [ ON UPDATE { NO ACTION | CASCADE | SET NULL | SET DEFAULT } ] [ NOT FOR REPLICATION ] | CHECK [ NOT FOR REPLICATION ] ( logical_expression ) } <table_index> ...
The SQLCREATE TABLEstatement is used to create a table. Syntax The basic syntax for creating a table can be given with: CREATE TABLEtable_name(column1_name data_type constraints,column2_name data_type constraints,... ); To understand this syntax easily, let's create a table in ourdemo...
您可以根据 SELECT 语句的结果创建表。 要创建此类型的表,请使用 CREATE TABLE AS 语句。 可以在 SELECT 语句中使用的所有表达式都可以在 CREATE TABLE AS 语句中使用。 您还可以包含要从中选择的一个或多个表中的所有数据。 例如,创建名为 EMPLOYEE3 的表,该表包含 EMPLOYEE 表中的部分列定义和数据,其中 WORK...
When creating a managed U-SQL table with a schema, a table schema has to be provided that contains at least one table column definition. Syntax Create_Managed_Table_With_Schema_Statement := 'CREATE' 'TABLE' ['IF' 'NOT' 'EXISTS']IdentifierTable_With_Schema. ...
Tip:For an overview of the available data types, go to our completeData Types Reference. SQL CREATE TABLE Example The following example creates a table called "Persons" that contains five columns: PersonID, LastName, FirstName, Address, and City: ...