Sql Server sql statement creates index

create index [index_mode] on [cn_name]([car_mode]);

index_mode custom index name

cn_name table name

car_mode column name

1. Create a common index
SQL CREATE INDEX syntax
Create a simple index on the table. Duplicate values ​​are allowed:

CREATE INDEX index_name
ON table_name (column_name);

Note: "column_name" specifies the column that needs to be indexed.

2. Create a unique index
SQL CREATE UNIQUE INDEX syntax
Create a unique index on the table. A unique index means that two rows cannot have the same index value.

CREATE UNIQUE INDEX index_name
ON table_name (column_name);

3. Example
CREATE INDEX Example
This example will create a simple index named "PersonIndex" in the LastName column of the Person table:

CREATE INDEX PersonIndex
ON Person (LastName);

4. Index Add Constraints
If you want to index the values ​​in a column in descending order, you can add the reserved word DESC after the column name:

CREATE INDEX PersonIndex
ON Person (LastName DESC);

5. Combined index
If you want to index more than one column, you can list the names of the columns in parentheses, separated by commas:

CREATE INDEX PersonIndex
ON Person (LastName, FirstName);