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catalogue 1, Prerequisites for database programming 2, Database programming in Java: JDBC 3, How JDBC works 4, Construction of development environment 5, JDBC programming in MySQL 1. Five step process 2. Add information 3. Query information 4. Delete information 5. Modify information 1, Prerequisites for database programming Pro ...

Understand the meaning and usage of table partition Master the traditional (10g and before) table partitioning method Master the table partition mode of 11g Allows users to divide a table into multiple partitions Users can execute queries and access only specific partitions in the table Different partitions are stored on different dis ...

1, MHA theory 1. MHA definition MHA (MasterHigh Availability) is a set of excellent software for failover and master-slave replication in MySQL high availability environment.The emergence of MHA is to solve the problem of MySQL single point.During MySQL failover, MHA can automatically complete the failover operation within 0-30 seconds.MH ...

seata distributed transaction of spring cloud Alibaba The construction of seata distributed transactions is scattered on the Internet, and there are always problems. Today, a chapter on building cases is published. This chapter is based on springcloud + Nacos + seate1 2 + MySQL build 1. First download seate1 Version 2 code and seate serve ...

Hive data type 1. Basic data type 2. Collection data type Case practice (1) Assuming that a table has the following row, we use JSON format to represent its data structure. The format accessed under Hive is { "name": "songsong", "friends": ["bingbing" , "lili"] , //List Array, "children": { //Key value Map, "xiao song": 18 , ...

Inner connection and outer connection The courseware comes from station b, Shangsi valley. Please move to station b for details All note links Inner join: merge the rows of multiple tables with the same column. The result set only contains the matching rows in the table #The following is the inner connection of MySQL 92: the result set is th ...

Grouping data This chapter describes how to group data so that you can summarize a subset of table content. This involves two new SELECT sentences, GROUP BY and HAVING clauses. Data grouping Last chapter( MySQL must know and know - Chapter 12 summary data )We use SQL aggregate functions to aggregate data. This allows us to count, calculate a ...

The TX-LCN framework explained today integrates three transaction modes: LCN, TCC and TXC. TX-LCN is an open source framework developed in China. You can see Chinese comments in the source code, which is more friendly. Let's talk about these three modes in detail, with code implementation. TX-LCN framework principle The framework is mainl ...

MySQL advanced supplement insert INSERT is used when inserting data into the table. In MySQL, it is data that can be inserted (lookup result table), but the order type of each column of the result table must be the same as that of each column of the table to be inserted, such as: --Create a file named jstudents Tables, storage id And nam ...

1: Cartesian product problem 1. Cartesian product: all records in multiple tables will match each other once. For example, if there are m records in Table 1 and n records in Table 2, Cartesian product will produce m*n records, such as select * from table 1 and table 2 2. In order to avoid Cartesian product, you can add effective connection con ...