Beginner MySQL Basic syntax

1 SELECT *  fromnew;2 SELECTStuname fromNew//Querying a column3 SELECT DISTINCTStuname fromNew//querying for different values in the same column4 SELECTColumn Name fromTable nameWHEREcolumn operator value;//conditionally querying the value of a column5 SELECTStuname,stuage fromNewWHEREStuname<> 'should fly'  andStuage=  A;//This symbol means not equal to<>Or!=6 SELECT *  fromYxfdb.newWHEREStuageinch(' A',' at');//inoperator allows us toWHEREspecify multiple values in a clause7 SELECT *  fromYxfdb.newWHEREStuage not between  A  and  -;//Operatorbetween... andA range of data between two values is selected. These values can be numeric, text, or date. 8 SELECT *  fromYxfdb.newWHEREStuname not  like '%xf%';//Using the LIKE query keyword,'y%'Y start with,'%y'Y end of the,'%xf%'contains the XF's9 SELECTStuname,stuage fromNewORDER  byStuname,stuage;//ORDER  byare letters and numbers sorted by default from small to largeTen SELECTStuname,stuage fromNewORDER  byStunameDESC, StuageASC;//DESCis sorted in reverse order, ASC is sorted by small to large One SELECTStuname,stuage fromYxfdb.new LIMIT5;//Query the first five data A SELECTNe.stuname, Ne.stuage fromYxfdb.new asNeWHERENe.stuname='should fly'  andNe.stuage=' -';//use as aliases to make the query program easier to read and write -  - SELECTYxfdb.new.stuname, Yxfdb.new.stuage, Yxfdb.info. ' Name ' the  fromYxfdb.info - INNER JOINyxfdb.new -  onYxfdb.info.id=yxfdb.new.id - ORDER  byYxfdb.new.stuname;// JOIN(INNERJoins within join intersection Left（ Right) Join LEFT join whichever is right or not, take out the left. Fulljoin fetch set) +  - SELECTE_name fromEmployees_china + UNION A SELECTE_name fromEmployees_usa//UNIONoperator is used to merge two or moreSELECTThe result intersection of the statement,UNION  Allis the set at  -SqlSELECT  intostatement can be used to create a backup copy of a table.  -  -  -  - INSERT  intoYxfdb.new (Stuname,stuage)VALUES('XF',' -'); in  -  to UPDATETable nameSETColumn Name=New valueWHEREColumn Name=a value;//Modify a row of data + UPDATEYxfdb.newSETStuname='Zhang San' WHEREId= 2 ; -  the  * DELETE  fromTable nameWHEREColumn Name=Value//Delete a column's value $ DELETE  fromYxfdb.newWHEREId= 1 ;Panax Notoginseng  -  the ALTER TABLEtable_nameADDCOLUMN_NAME datatype;//Add a column + ALTER TABLEtable_nameDROP COLUMNcolumn_name;//Delete a column A ALTER TABLEtable_nameALTER COLUMNcolumn_name date;//Modify the data type of a column the ALTER TABLEPersonsADD PRIMARY KEY(id_p);//Modify Id_p Primary key +  - CREATE DATABASEmy_db $  $ CREATE TABLEOrders - ( -Id_oint  not NULL, theOrderNoint  not NULL, -Id_pint,Wuyi PRIMARY KEY(id_o), the FOREIGN KEY(id_p)REFERENCESPersons (id_p) -)//Create tables and set primary and foreign keys Wu  -  About ALTER TABLESocial $ ADD FOREIGN KEY(id_p) - REFERENCESinfo (id_p);// -  - CREATE TABLEPersons A ( +Id_pint  not NULL PRIMARY KEY, theLastNamevarchar(255), -FirstNamevarchar(255), $Addressvarchar(255), theCityvarchar(255), the UNIQUE(id_p) the ) the  -  in It is also possible to select data from more than one table.  the The following example creates a new table named "Persons_order_backup" that contains the information obtained from the Persons and Orders two tables: the SELECTPersons.lastname,orders.orderno About  intoPersons_order_backup the  fromPersons the INNER JOINOrders the  onPersons.id_p=Orders.id_p

Beginner MySQL Basic syntax