sql query with nolock

(*), sex from student group by sex;Grouping statistics by age and gender combination and sortingSelect COUNT (*), sex from student group by sex, age order by age;Grouped by gender and are records with IDs greater than 2 finally sorted by sexSelect COUNT (*), sex from student where ID > 2 GROUP by sex Order by sex;Querying data with IDs greater than 2, and grouping and sorting results after completion of operationsSelect COUNT (*), (Sex * ID) New from student where ID > 2 GROUP BY sex * ID of OR

Pq_distribute hints are often used to improve the performance of connection operations between partitioned tables in the Data Warehouse. The Pq_distribute hint allows you to determine how table data rows participating in a connection are allocated between production and consumption parallel query service processes. Pq_distribute prompt accepts three parameters: table name, outer allocation, and internal allocation.When parallel

Partii:sql BasicsCHAPTER 4Creating a simple Querydescribes a way to create SQL the technology of the statement -- "Request/translation/clean up/sql "The SELECT operationin SQL can broken down into three smaller operations,Which we'll referto as the select statement,the Select expression,and the SelectQuery.The first layer contains one layer , nesting with each o

Now the development system involves querying by page. when doing this, I am thinking, whether or not the query SQL statement can be automatically encapsulated by parameters into the ability to count the data size of the query statement that is not queried by page. for example, the general practice is: 1. first query ba

, generating VT6. has: has a having filter applied to VT6. Only groups that make Select: processes the select list, producing VT8. DISTINCT: removes duplicate rows from VT8, resulting in VT9. ORDER BY: generates a cursor (VC10) by sorting the rows in VT9 by the list of columns in the ORDER by clause. TOP: selects the specified number or scale of rows from the beginning of the VC10, generates the table VT11, and returns the caller. Note: Step 10, this

--select select * from student; --all query All the Select all sex from student; --DISTINCT filtering repeats select distinct sex from student; --count Statistics SELECT COUNT (*) from student; Select count (Sex) from student; Select count (Distinct sex) from student; --top fetch top N Records select Top 3 * from student; --alias Column name rename named Select ID as number, name ' names ', sex gender from student; --alias Table Name table rename Sele

Analysis of SQL Server's focus on using indexes and query execution plans and SQL Execution plans Preface In the previous article "Analysis of the Impact of SQL Server focused indexes on non-clustered indexes", we talked about the impact of clustered indexes on non-clustered indexes and the performance optimization tha

In SQL ServerEach database has a table generated by the system.The table sysobjects records all the table names in the database.We can use the following SQL syntax for query operations. Copy codeThe Code is as follows:Select Name, id from sysobjects where xtype = 'U' Xtype = 'U' indicates the table used. If xtype = 's' is used'The default table There is also a

Check this diary record SELECT * FROM Messages WHERE convert (Nvarchar, createdate, MR) = CONVERT (Nvarchar, GETDATE (),) Order by CreateD Ate DESC SELECT * from table WHERE DateDiff (day, column name , GETDATE ()) =0 Check this year SELECT Count (*) from Messages WHERE DateDiff (year,createdate,getdate ()) =0 Query this month SELECT Count (*) from Messages WHERE DateDiff (month,createdate,getdate ()) =0 This week 's record SELECT * from

a joins Dept b on (a.deptno = B.deptno) Order BY empno Desc;To sort by an alias of a field or an expressionSelect A.ename,a.mgr,a.empno, (a.sal*12) as annsal from EMP a order by annsal;1.5 GroupingSelect B.deptno,b.dname,sum (a.sal)From EMP a,dept bwhere A.deptno=b.deptnoGROUP BY B.deptno,b.dnameORDER BY B.deptno DescFields after GROUP by = ALL display fields except aggregate functions in the select listThe total wage, the number of people, the maximum wage, the minimum wage, the average wage o

The SELECT clause is logically the last step in the final processing of the SQL statement, so the following query will have an error: SELECT year (OrderDate asorderyearCOUNT(DISTINCT CustomerID fromdboGROUP by OrderYear; Because group by was preceded by a SELECT, the OrderYear column was not formed at that time. If you want to query for su

Theoretical background1. sql:structured Query Language is the standard language for querying and managing data for RDBMS (relational Database Management Systems).2. Understanding set theory and predicate logic, RDBMS is based on these two mathematical branches.3. SQL statement Category:Data definition Language, DDL: The definition language, which handles the definition of objects, including statements such

In the process of paging data using temporary tables, it is found that the query statement conditions are passed through the stored procedure parameters. The parameter conditions cannot be directly used after the SQL where statements are added. There is only one solution to this problem, it is to concatenate SQL statements and conditions into an

This issue is especially important for projects with a relatively large scale. If there are hundreds of stored procedures in the database,I can't find them one by one. Even if I understand the business and system very well, it will take a long time to remember.How can I use SQL statements for queries?The following describes how to query SQL statements:Copy codeTh

--Find all parent nodesWith TAB as(Select Type_id,parentid,type_name from sys_paramtype_v2_0 where type_id=316--child nodesUNION ALLSelect B.type_id,b.parentid,b.type_nameFromtab a,--child node datasetsSys_paramtype_v2_0 B--parent node data setWhere a.parentid=b.type_id--the child node DataSet. Parendid= The parent node data set. Id)SELECT * from tab;--Find all child nodesWith TAB as(Select Type_id,parentid,type_name from sys_paramtype_v2_0 where type_id=1--parent nodeUNION ALLSelect B.type_id,b

Tags: style time span stat name not sel tab DUPI'm using a statement to save the queried data to a new table 1) using the into table statement, the new table that needs to be saved does not need to be created in advance Select * to from table-Insert new Table statement into TableName 2) using the Insert Table statement, the new table that needs to be saved does not need to be created in advance CREATE TABLE [dbo].[newtable]( [Fdsequenceid][bigint] not NULL, [Fdinnertime][Da