sql add, delete, modify and check syntax

1. sql insert syntax

1. Use insert to insert a single row of data
   Syntax : insert [into] <table name> [column name] values ​​<column value>
   Example: insert into Strdents (name, gender, date of birth) values ​​('bin','male',' 1993/6/15')
   Note: into can be omitted; column names and column values ​​are separated by commas; column values ​​are enclosed in single quotes; if the table name is omitted, all columns will be inserted in turn

Second, sql delete syntax

1. Use delete to delete some data
   Syntax : delete from <table name> [where <deletion condition>]
   Example: delete from a where name='bin' (delete the row whose column value is "bin" in table a)
   Note : Deleting the entire row is not deleting a single field, so the field name cannot appear after delete
   Note : When deleting data, be sure to add the where condition

Three, sql insert data

1. Use update to update and modify data
   Syntax : update <table name> set <column name=update value> [where <update condition>]
   Example: update tongxunlu set age=18 where name='blue nickname'
   Note: after set It can follow the update values ​​of multiple data columns, separated by commas; the where clause is optional and used to restrict conditions. If not selected, all rows of the entire table will be updated.

Four, sql query statement

1. Common query
   Syntax : select <column name> from <table name> [where <query condition expression test>] [order by <sorted column name>[asc or desc]]
  

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