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KingbaseES logical backup and restore tool provides online backup and restore function at database object level. Backup objects include: database pattern surface view constraint jurisdiction trigger function sequence The output format of logical backup includes: Binary SQL script In addition, for table data, it also supports the e ...

1. How to synchronize database with ES We all know that ES is a search engine. Its search speed is much faster than that of the database. How to synchronize the contents of the database to es? The middleware Logstash is needed at this time. Logstash is an open source data collection engine with real-time pipeline function. Logstash can ...

1. Bitwise operator Bitwise operators are operators that evaluate on binary numbers. The bit operator first converts the operand into a binary number, then performs a bit operation, and finally changes the calculation result from binary to decimal. MySQL supports the following bitwise operators: 1.1 bitwise and operators The bitwise ...

Core content of MySQL execution plan As we all know, mysql performs query optimization when executing queries. To put it simply, when executing, first generate an execution plan based on cost and rule optimization, and then execute the query according to the execution plan. This article mainly introduces the meaning of each output item of EXPL ...

[tcallusdb knowledge base] restfulapi2 0 for generic table - [PB] FieldGetRecord introductionbrief introductionThe corresponding field selected in the auto increment record only works on numeric type fields. It is often used in scenes such as players' experience value increase and level increase to avoid checking and updating first and reduce n ...

[tcallusdb knowledge base] restfulapi2 0 for list table - [Pb] listgetrecord2 0 Introductionbrief introductionQuery the record of the specified subscript under the corresponding Key in the List PB table.Index: Specifies the subscript of the record to return.POST http://{Tcaplus_REST_URL}Request syntaxHttp request#Tencent cloud console RESTful E ...

1, Prepare test environment 1.1. Create data table /* Employee table */ CREATE TABLE `emp` ( `id` int(8) NOT NULL AUTO_INCREMENT, `name` varchar(20) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL DEFAULT '', `job` varchar(9) NOT NULL DEFAULT '', `hiredate` date NOT NULL, /* Entry date */ `sal_grade` int(8) NOT NULL, `age` ...

1, One to one mapping Suppose that in the permission system, a user can only have one role, that is, the relationship between users and roles is limited to one-to-one relationship. 1.1 handling one-to-one relationships using automatic mapping A user has a role. We add the role class SysRole field in the user class SysUser. As follows: publi ...

Introduction: this chapter mainly explains the related technologies of dynamic web page crawling. The crawling of dynamic web pages mainly includes reverse analysis method and simulation method. Today, we will mainly introduce the reverse analysis method. Later, we will focus on the use of selenium Library in the simulation method. Dynamic ...

catalogue After the execution of SQL statements in MyBatis, the processing of results     1. resultType result type refers to the java object that the data is converted to after the sql statement is executed. The java type is arbitrary     2. Alias the resultType of the returned result     3. Save q ...