convert linq query to sql query online

SQL query statement "3": Multi-Table query (also called connection query, which is a connection query based on two tables)If a query needs to operate on multiple tables, it is called a connection

1.in when the query condition is ListSelectId="getmultimomentscommentscounts"Resulttype="int">SelectMoment_comment_count fromTbl_moment_commentcountwhereMidinchforeachitem="Item"index="Index"collection="List"open="("Separator=","Close=")">#{item}foreach> Select>.1 if the type of the parameter is list, then when used, the collection property must be specified as a list select id= "findbyidsmap" resultmap="Baseresultmap"> Select include refi

Connection Query You can use the join operator to query multiple tables. Connection is the main feature of the relational database model and a symbol that distinguishes it from other types of database management systems. In the relational database management system, the relationship between data does not have to be determined when a table is created, and all information about an object is often stored in a

Grade> = 90 -- Use "logical expression" as the query condition ...... /* Logical expressions in SQL: Not: non And: corresponds Or: or */ Select * from Student -- Query the student table for a 19-year-old male student. Select * from Student where Sage = 19 and Ssex = 'male' -- Query the student whose age is 19 or 20 in

most complex, but also the focus of tuning. At present, the application of database is divided into two types of online transaction processing (oltp,online Transaction processing) and decision support System (Dss,decision Support System), which have different requirements for query. OLTP mainly involves a single table, simple

Query and delete SQL statements of Repeated Records and query SQL statements of records SQL statement for querying and deleting duplicate records1. Search for redundant duplicate records in the Table. duplicate records are determined based on a single field (peopleId ).Selec

Next: T-SQL Dynamic Query (1)--IntroductionObjective:In the development of features, we often encounter scenarios such as the following: The application has a query function that allows the user to select the desired condition in many query conditions. This is also the focus of this series.But sometimes you may find th

Label:3-4 using the Entity SQL query modelProblem 　　You want to query your Entity Data model and return strongly typed objects by executing an Entity SQL statement. Solution Solutions Suppose you have the model shown in Figure 3-5, which contains a customer entity type. This entity type has a name attribute and an emai

SQL query (Note 2--entity query)Second, the entity queryIf the query returns all of the data columns for a data table, and the data table has a corresponding persisted class map, we convert the query results into entity queries. Y

Label:Original Ode-tsql convert Query to JSONTsql-query to JSONIt is my philosophy, good development starts with the data. I have all stressed whenever possible allow your data processing to take place on your SQL Server or database Processin G engine and rendering of the data to the application control engine. By the

Advanced query technology is mainly related to multiple tables linked query technology, embedded SELECT statement subquery technology, the combination of multiple queries combined technology. 1. Connection Query You need to retrieve data from two or more tables at the same time. A link allows you to retrieve data from two tables or more than two tables at the s

How does the column selection differ when Oracle queries are converted to SQL queries? The following describes how to select columns from Oracle query to SQL query. We hope that you can have a deeper understanding of Oracle query. When converting an Oracle

SQL, Structured query Language Structured Query Language , is a database query and programming language for accessing data and querying, updating, and managing relational database systems. SQL language contains 4 sections:※ data definition language (DDL) create ,

Label:Recently encountered a more interesting problem in the project, the online search for some methods, summarized here to share. We often encounter such a scenario: the need to query data, there are some query conditions, but when the query, we hope that when a condition is empty, then do not filter this condition,

), variable length, can hold photos, files, etc. int, integer field. Example: Userage int float, floating-point data is approximate. Example: Userresults float, the approximate numeric data type used to represent floating-point numeric data. datetime, Date type. Example: Createdatetime datetime Bit, Boolean type. Can be set to True is male, false is schoolgirl If the content is very much, indeterminate length (such as article), can be used: nvarchar (max) 6. Save the tabl

Optimization of SQL massive data query and non-use like processing solutions, data query like 1. To optimize the query, try to avoid full table scanning. First, consider creating an index on the columns involved in where and order. 2. Try to avoid null value determination on the field in the where clause. Otherwise, th

Optimization of SQL massive data query and non-use like processing solutions, data query like 1. To optimize the query, try to avoid full table scanning. First, consider creating an index on the columns involved in where and order.2. Try to avoid null value determination on the field in the where clause. Otherwise, the

This article describes how to convert URL strings and query strings in nodejs. For details, refer to the next complete URL string from "? "(Excluding ?) To "#" (if # exists) or end with the URL string (if # does not exist), this part is called a query string. You can use the parse method in the Query String module to

code as follows: SELECT sname from Student WHERE sname like ' Zhang% '; 30, query the same-sex students list, and statistics of the same name number Copy Code code as follows: Select Sname,count (*) from Student GROUP by Sname has count (*) >1; 31. List of students born in 1981 (note: The type of the sage column in the student table is datetime) Copy Code code as follows: Select Sname,

1T-SQL advanced query Statement2 3 Advanced Query4 51. Connection query,extensions to the result set column6SELECT *From info7 8SELECT * FROM Info,nation#To form a Cartesian product9SELECT * from Info,nation where info.nation=nation.CodeTenSelect Info.code,info.name,sex,nation.name,birthday from Info,nation where info.nation=nation.Code One ASELECT * FROM InfoJo