Some common SQL query statements

Study site: http://www.w3cschool.cc/sql/sql-tutorial.html One: Querying the properties of all tables

SELECT     'ALTER TABLE'+    Case  wheno.schema_id is  not NULL  Then(SELECTNAME+'.'  fromSys.schemasWHEREschema_id=O.SCHEMA_ID)ELSE "' END  +object_name(parent_object_id)+'DROP CONSTRAINT'+object_name(object_id)+': On UPDATE cascade on DELETE Cascade'  fromSys.objects asOJOINSys.schemas asS ono.schema_id=s.schema_idWHEREO.typeinch('C','D','F','UQ')   SELECT  *   frominformation_schema. Table_constraintswheretable_nameinch(' Book','Borrow','Reader')--object_id (Object_name,object_type)--Object Type:--AF = aggregate function (CLR)--C = Check constraint--D = DEFAULT (constrained or standalone)--F = FOREIGN key constraint--FN = SQL scalar function--FS = Scalar function of the General Assembly (CLR)--FT = assembly (CLR) Table-valued function--IF = SQL Inline table-valued function--IT = Internal table--P = SQL stored Procedure--PC Assembly (CLR) stored Procedures--PG = plan guide www.2cto.com--PK = PRIMARY key constraint--R = Rule (Legacy, standalone)--RF = replication filtering process--S = System base Table--SN = synonym--SQ = Service queue--TA = component (CLR) DML trigger--TF = SQL table-valued function--TR = SQL DML trigger--TT = Table Type--U = table (user defined)--UQ = Unique constraint--V = View--X = extended stored Procedure

II: Classic SQL statement Daquan

Original: http://www.cnblogs.com/yubinfeng/archive/2010/11/02/1867386.html

Three: Query which tables appear in a field

SELECT   *    from   Information_schema. COLUMNS   WHERE   column_name='rankname'

Some common SQL query statements