MySQL (iv)--records in the operational data sheet

• Inserting records

  • INSERT [ into]Tbl_name[(col_name,...)]{VALUES |VALUE} ({expr| DEFAULT},...),(...),...//Law Two: The difference is that this method can use subqueries (subquery)INSERT [ into]Tbl_nameSET col_name={Expr|DEFAULT},...//method Three: This method can insert the query result into the specified data tableINSERT [ into]Tbl_name[(col_name,...)] SELECT...

• Update record (single table update)

  •  update  [ Span style= "color: #ff0000;" >low-priority   [ ignore   table_reference set  Span style= "color: #000000;" >col_name1  =  {expr1|  default } [ ,col_name2 = {expr2| DEFAULT}     ...  [ where where_condition  ]

• Delete Record (single table Delete)

  • DELETE  from [WHERE where_condition]

• Find Records

  • SELECTselect_expr[, select_expr ...][From table-references [WHERE where_condition]    [GROUP by {col_name | position} [asc| DESC], ...] [Having where_condition]    [ORDER by {col_name | expr | position} [asc| DESC], ...] [LIMIT {[Offset,]Row_count|row_count offset (offset}] ]

  • Each expression expresses the desire for a column, which must be at least one;
  • Comma-equal between multiple columns;
  • A query expression can use [as] alias_name to give it an alias;
• Conditional expression--where
  • Filter the record, and if no WHERE clause is specified, all records are displayed;
  • In the where expression, you can use the functions or operators supported by MySQL.
• Query result grouping--group by
• Grouping conditions--having
• Limit the number of query results returned--LIMIT

MySQL (iv)--records in the operational data sheet