tricky sql queries

The nine forms of Select queries in the LINQ to SQL statements, linqsqlDirectory Description Simple Form Anonymous type Condition form Type format Filtering form Shaped format Nested form Local call method form Distinct form Description Similar to the select statement in SQL commands, the query expression select is placed at the end of the expression.

Tags: ring UNC warnings DDE LIS RET query Public currentPublic listString sql= "SELECT * from Inter_product_msg A WHERE a.productid=? ";SQL querysqlquery sq = this.getcurrentsession (). createsqlquery (SQL). addentity (Interproductmsg.class);Sq.setstring (0, productId);@SuppressWarnings ("Unchecked")listLogutil.writelog ("DAO Implementation Layer" +list);return l

Tags: exec add update insert LED link server local DSR columnCreate a linked server exec sp_addlinkedserver ' itsv ', ' ', ' SQLOLEDB ', ' Remote server name or IP address 'exec sp_addlinkedsrvlogin ' itsv ', ' false ', NULL, ' username ', ' password ' --query ExampleSELECT * from ITSV. Database name. dbo. Table name --import ExampleSELECT * into table from ITSV. Database name. dbo. Table name --Remove linked server when no longer in useexec sp_dropserver ' itsv ', ' droplogins ' --Connect remot

generate the virtual table VT4. 5.SELECT: Processes child elements in SELECT and generates virtual table VT5. 5-1. Evaluate expression: Processes the calculation expression in the select list, generating Vt5_1. 5-2.DISTINCT: Handles duplicate rows in the Vt5_1, generating vt5_2. 6.ORDER by: Sorts Vt5_2 to generate a cursor VT6 6-1. Column aliases in the select list are already available in this step The 6-2.order by clause is applied to the final result set, so when keywords such as union appea

The efficiency of Multi-table join queries has been a topic discussed by our developers. I will share some of my tests when using multi-table queries with you, I hope to help you all. I encountered A problem when I was working on the website recently. I need to output two fields in Table B and Table C. However, the variable obtained by the program is the id in table, table A is associated with table B and T

Label:When using hibernate SQL queries in multi-table queries, the object[] array is generally returned, or you can use the Session.createsqlquery (SQL). Setresulttransformer (Transformers.alias_to_entity_map); To map for processing, you can turn query results into entity classes in the following ways: 1,

Query table: select * fromsys. objectswheretypeU query Stored Procedure select * fromsys. objectswheretypeP query Stored Procedure content EXECSp_HelpText stored procedure name query User-Defined Function select * fromdbo. Explain query User-Defined Function content EXE Query table: select * from sys. objects where type = 'U' query the Stored Procedure select * from sys. objects where type = 'P' queries the Stored Procedure content EXEC Sp_HelpText '

Tags: Inner SQL UNION All-color SEL tab Select from useTable1 table with infinite hierarchy, ID (primary key), ParentID (parent ID) queries all subordinates or all ancestors of an ID, using the WITH as,union all query1, the query ID is 1 all subordinate withT as( SELECT * fromTable1WHEREId=1 UNION All SELECTA.* fromTable1 AINNER JOINT onA.parentid=t.id)SELECT * fromT2, the query ID is 88 all

, Ss.sum_total_logi Cal_writes from (SELECT s.plan_handle, SUM (s.execution_count) Sum_execution_count, SUM (s.total_elapsed_time) sum_total_elapsed_time, sum (s.total_worker_time) Sum_total_worker _time, sum (s.total_logical_reads) sum_total_logical_reads, sum (s.total_logical_w Rites) sum_total_logical_writes from Sys.dm_exec_query_stats s GROUP by S.plan_handle) As SS Cross APPLY sys.dm_exec_sql_text (ss.plan_handle) T ORDER by Sum_total_logical_reads DESC

T3 on T1.userid=t3.useridRun Result: UserID username password userid JF DJ1 Jack Jackpwd 1 20 3NULL NULL NULL 3 50 6IV: FULL OUTER JOIN displays all rows in both tablesSELECT * FROM T1 full outer join T3 on T1.userid=t3.useridRun Result: UserID username password userid JF DJ1 Jack Jackpwd 1 20 32 Owen OWENPWD null NULL NULLNULL NULL NULL 3 50 6Summary, on the joint inquiry, I have already tested. The efficiency is indeed relatively high, 4 kinds of Union way if can use flexibly, basically compl

MySQL queries the SQL statements used for data from today, this week, last week, this month, last month, this quarter, last quarter, and last year. Recently, due to work requirements, various report data needs to be collected. SQL statements are written in ultra-long and ultra-complex ways. Now, we only summarize some basic S