elasticsearch query all

Tags: filter recommended mysql 2-2 First merge Karl join display1. Preparation of two tables Table A Table B 2. Test the connection query: (1) Cross connection (Cartesian product) SELECT * from a a B 　　 (2) Inner connection Show internal connections SELECT a.*,b.* from a INNER JOIN B on A.age=b.ageb display the INNER join filter Condition: SELECT a.*,b.* from a INNER JOIN B on A.age=b.ageb have a.age=11 Hermit inside Connection: SELE

1. Query All TablesSelect [ID], [name] from [sysobjects] where [type] = ' u ' ORDER by [name]2. Query all databases3. Select [Name] from [sysdatabases] ORDER by [name]Querying fields in a tableSelect [Name] from [syscolumns] where [name] = ' tablexxx ' ORDER by [Colid]Oracle1. Find

MySQL Federated Query Union and UNION ALL usage IntroductionThe function and syntax of union and UNION allThe UNION is used to combine the result set of two or more SELECT statements and eliminate any duplicate rows in the table.The SELECT statement inside the UNION must have the same number of columns, and the column must have a similar data type.Also, the order of the columns in each SELECT statement must

Tags: SCH TEST get LSE ASE ATI Case Property End1./* Query database Test all table comments */SELECT from WHERE Table_schema='test';2, to query the table field commentsSELECT from WHERE table_name='class' and Table_schema=' test';3, one-time query database "test" the following table comments and corresponding table

1, using the sysobjects system table in this table, each object created in the database (for example, constraints, defaults, logs, rules, and stored procedures) has a row, and we filter out all the records in the table that are xtype equals u, which is the table in the database. The example statements are as follows:SELECT * from sysobjects where xtype= ' U 'Note: In SQL SERVER2005, the sys.objects catalog view appears in place of the sysobjects syste

Label:--Execute directly in the library where you need to query.SELECT ( CaseWhen a.colorder=1Then D.nameElse NULLend) Table name, A.colorder field ordinal, a.name field name, ( CaseWhen ColumnProperty (A.id,a.name,'isidentity')=1Then'√'Else "'end) identification, ( CaseWhen (SELECT count (*) from sysobjects WHERE (nameinch(SELECT name from sysindexes WHERE (ID= a.ID) and (indidinch(SELECT indid from Sysindexkeys WHERE (ID= a.ID) and (colidinch(SELECT colid from syscolumns WHERE (ID= a.id) and (

Public ArrayList getallpersons (){ArrayList arrpersons = new ArrayList ();Connection conn = null;try {Class.forName ("Org.gjt.mm.mysql.Driver");conn = Drivermanager.getconnection ("Jdbc:mysql://localhost:3306/persondb", "root", "root");String sql = "SELECT * from T_person";PreparedStatement PSMT = conn.preparestatement (sql);ResultSet rs = Psmt.executequery ();while (Rs.next ()){String pid = rs.getstring (1);String pname = rs.getstring (2);int age = Rs.getint (3);float height = rs.getfloat (4);f

constraint constraint_name 禁用外键约束的命令为：alter table table_name disable constraint constraint_name然后再用SQL查出数据库中所以外键的约束名：select ‘alter table ‘||table_name||‘ enable constraint ‘||constraint_name||‘;‘ from user_constraints where constraint_type=‘R‘select ‘alter table ‘||table_name||‘ disable constraint ‘||constraint_name||‘;‘ from user_constraints where constraint_type=‘R‘14、ORACLE禁用/启用外键和触发器 --启用脚本SET SERVEROUTPUT ON SIZE 1000000BEGINfor c in (select ‘ALTER TABLE ‘||TABLE_NAME||‘ ENABLE CONSTRAINT

Package Com.lc.view;import Java.util.iterator;import Java.util.list;import org.hibernate.session;import Org.hibernate.transaction;import Com.lc.domain.student;import Com.lc.utils.hibernateutil;public Class selectstudent {public static void main (string[] args) {selectsomestudents ();} /* * 1. Retrieve all students */public static void Selectallstudents () {session session = NULL; Transaction ts = null;try {session = Hibernateutil.getcurrentsession ();

--Merge duplicate rows select * FROM Aunion SELECT * from b--do not merge duplicate rows select * FROM Aunion allselect * from B Sort by a field-merge duplicate row select *from (sele CT * FROM Aunion select * to B) as Torder by field name--Do not merge duplicate rows select *from (SELECT * FROM Aunion allselect * from B) as Torder By field name//sql Server version SELECT * FROM (select top 2 id,adddate,title,url from barticle where classid=1 order by adddate Desc) Aunion Allselect * FROM (sele

SELECTUser_tab_cols. table_name astable name, Utc.comments astable Chinese name, User_tab_cols. column_id ascolumn ordinal, User_tab_cols. column_name ascolumn name, User_tab_cols. Data_type asdata type, User_tab_cols. Data_length aslength, User_tab_cols. NULLABLE asIs empty, user_col_comments.comments asNotes fromUser_tab_cols Left Joinuser_tab_comments UTC onUser_tab_cols. table_name=Utc.table_nameInner Joinuser_col_comments onUser_col_comments. table_name=User_tab_cols. TABLE_NAME andUser_col