sql server fuzzy string comparison

In SQL Server, the Inner Join and Outer Join operations between common tables are performed by the execution engine based on the selected columns and whether the data has an index, the selected data is selectively converted to one of the Loop Join, Merge Join, and Hash Join physical connections. Understanding these three physical connections is the basis for solving performance problems during table connect

SQL Server PRIMARY key notation:--Column levelCreate TableDept (dept_noint Primary Key, Dept_name nvarchar (20) not NULL)--table-levelCreate TableDept (dept_noint not NULL, Dept_name nvarchar (20) not NULL,Primary Key(Dept_no)) --ModificationCreate TableDept (dept_noint not NULL, Dept_name nvarchar (20) not NULL);Alter TableDeptAdd Primary Key(DEPT_NO)--Add a primary key namealter table dept Add constrain

A good database is very important ., Provides some reference for you to select a database This article compares SQL Server in some aspects. Openness SQL Server can only run on Windows. Reliability, security, and scaling critical business ., Without any openness, the operating system is more focused on desktop applicati

In SQL Server, the inner join,outer Join that is common between tables and tables is executed by the engine based on the selected column, whether the data is indexed, and the selectivity of the selected data is converted to loop Join,merge Join,hash Join one of the three physical connections. Understanding that these three physical connections are the basis for solving performance problems when tables are c

When we build a database and want to aggregate the different types of databases scattered across the database in this new database, especially when it comes to data validation, decontamination, and transformation, there are big challenges. Fortunately, SQL Server provides us with powerful, rich data import and export capabilities, and when importing exports, we can flexibly handle the data. There are three

Database System class The teacher introduced 2 kinds of databases: Oracle database and SQL Server, also said the difference between their schema (schema, also known as architecture), here I also add with my common MySQL pattern differences, the memo. A pattern is equivalent to a namespace in a database system where multiple objects, such as basic tables, views, and indexes, can be used. To access an object

functions are used to obtain the midnight time point. Select dateadd (DD, datediff (DD, 0, getdate (), 0) Go deep into datediff and dateadd function compute You can understand that by using simple datediff and dateadd functions, you can find many different dates that may be meaningful. All the examples so far only calculate the number of time intervals between the current time and "1900-01-01", and then add it to the "1900-01-01" time interval to calculate the date. If you modify the number

)RETURN 1ELSESET @ fStr = SUBSTRING (@ fStr, @ I + LEN (@ doc), LEN (@ fStr ))ENDENDRETURN 0END Version 2: Comparison by words Algorithm concept: extract the search string loop by word and compare the characters to be searchedCopy codeThe Code is as follows:USE [Fly]GO/***** Object: UserDefinedFunction [dbo]. [CGF_FN_SearchChar] Script Date: 09/03/2010 16:42:12 ******/SET ANSI_NULLS ONGOSET QUOTED_IDENTIFIE

BY ID Paging Scheme two: (with ID greater than how much and select top pagination)Statement form: Copy Code code as follows: SELECT Top * from testtable WHERE (Id > (SELECT MAX (ID) from ( SELECT Top ID from TestTable order by ID) as (T)) Order by ID SELECT top Page Size * from testtable WHERE (ID N bsp; (SELECT MAX (ID) from (SELECT top page size * pages ID from table order by ID) as (T)) Order by ID Pag

The access and SQL server data types are different. These types are useful when you use scripts to define data. Microsoft Access Data Type SQL Server Data Type Yes/No Bit Smallint (byte type) Tinyint Integer (long Integer) Int Real (single precision floating poi

Tags: font SQ Temporary IMA SQL tab PNG way BubukoSQL Traversal parsingIn SQL stored procedures, functions, it is often necessary to use traversal (traversal table), where a cursor, temporal table, and other traversal methods are common. In the face of small data volume, these kinds of traversal methods are feasible, but faced with large data volume, it is necessary to select the preferred, different traver

time, we are forced to change the password first. at the beginning, you may wonder if the newly created user is locked. after oracle is installed, some users such as Scott are locked by default. you can unlock it like this. AlterUserScott accountunlock; If you want to lock Scott, it will naturally be alter user.Scott accountlock; However, the new user does not belong to this situation or has no permission. only connecting to the database requires a separate permission. (This permission is not a

Tags: des style blog http using IO data forThe test that appears in the following SQL Server and MySQL is a table (except for special instructions)1. View the script created by the tableSQL Server:Mysql:Show create TABLE test;2. View table structureSQL ServerSp_columns test;OrSp_help test;Mysql:Show columns in test;OrDESC test;3. See which tables are in the databaseSQL Server:Select name from sysobjects whe

Comparison of Date field values in SQL ServerThere are a number of ways to compare Date fields in SQL Server, which are described in several common ways:Use the Employees table in the Northwind library as the use Case table.1.BetweenThe use of the ... and statement:DescriptionBetween... and for specifying the test scop

syntax structure: 1. Cast Syntax structure: CAST (expression as data_type [(length)]) 2. Convert Syntax structure: CONVERT (data_type [(length)], expression [, style]) 3. Parse Syntax structure: PARSE (string_value as data_type [USING culture]) Where Parse is a new feature of SQL Server expression must be a string form of the converted Type Performance Analysi

(2,147,483,647) characters. String Unicode string NChar Fixed-length Unicode data with a maximum length of 4,000 characters. String nvarchar Variable-length Unicode data with a maximum length of 4,000 characters. sysname is a system-supplied user-defined data type that is functionally equivalent to nvarchar, w

=DBO.FN_GET_FUZZY_STR (@match_str); return Case when @src_str like @fuzzy_str Then 4000 + + - Len(@src_str) when(Len(@fuzzy_str)- @setp*2*1 >= 5) and @src_str like Left(@fuzzy_str,Len(@fuzzy_str)- @setp*2*1) Then the + + - Len(@src_str) when(Len(@fuzzy_str)- @setp*2*2 >= 5) and @src_str like Left(@fuzzy_str,Len(@fuzzy_str)- @setp*2*2) Then - + + - Len(@src_str) when(Len(@fuzzy_str)- @setp*2*3 >= 5) and @src_str like Left(@fuzzy_str,Len(@fuzzy_str)- @setp*2*3