convert json to mysql table

1. Background* temporary table is session-based, only visible on current connection* When this connection (session) is closed, it will be automatically drop. * two different connections (sessions) Use the same temporary table name and do not conflict with each other, or use a table that already exists, but not a table

this list)HOUR ()MICROSECOND ()MINUTE ()MOD ()MONTH ()QUARTER ()SECOND ()TIME_TO_SEC ()TO_DAYS ()WEEKDAY ()YEAR ()YEARWEEK ()Note:Because the partition function does not include the FROM_UNIXTIME function, you cannot use the timestamp to convert the time to partition. You can only use date or datetime to partition.For example, we can use:Partition by range (YEAR (date ))Monthly:Partition by range (date div 100)# Div converts a date to an integer. For

, even if they are the same, the change syntax still requires two column names. For example:Mysql> alter table T1 change B bigint not null;However, in mysql3.22.16a, you can also use modify to change the column type rather than rename it:Mysql> alter table T1 modify B bigint not null;If you use change or modify to shorten a column, an index exists in the column section (for example, if you have an index wit

Mysql modifies database encoding (database character set) and table character encoding method bitsCN.com Mysql converts the character encoding of a table to UTF-8.Alter table tb_anniversary convert to character set utf8; Modify

, oracle takes 2 seconds) Is there a big performance gap between InnoDB, a MySQL transaction type table ??? The test process of Sybase and Oracle is attached: Sybase test Stored Procedure createproceduresp_AAA as begin declare@iinteger declare@a1char(64) declare@b2char(255) select@i=1 while@i begin select@a1=‘aaa’+convert(varchar(6

shaping need to convert it to shaping through a function. mysql-5.5 begins to support the columns partition, which can be considered as the evolution of the range and list partition, and the columns partition can be partitioned directly using non-shaping data. The columns partition supports the following data types: All shaping, such as int SMALLINT TINYINT BIGINT. float and decimal are not supported. Date

) The larger the number, the less accurate * * *function: Store salary, height, weight, physique parameters, etc. character type: char (m) the char data type is used to represent fixed-length strings and can contain up to 255 characters. where m represents the length of the string. PS: Even if the data is less than m length, it will also occupy the m length, but in the query, the detected results will automatically delete the trailing space features: fixed length,

optimize requires sufficient hard disk space. Otherwise, the table may be damaged and cannot be operated. Use repair. Note that INNODB does not support repair.Generate a disordered idMethod: Use a preset table For example, id and toid ing The id is fixed, and the toid is random. Record a pointer value in redis or memcache, pointing to the id When you want to obtain a new toid, retrieve the pointer value, a

: Mysql> SELECT artists.Artist, cds.title, genres.genre FROM cds LEFT JOIN genres N cds.genreID = genres.genreID LEFT JOIN artists ON cds.artistID = artists.artistID; Or mysql> SELECT artists.Artist, cds.title, genres.genre FROM cds LEFT JOIN genres ON cds.genreID = genres.genreID LEFT JOIN artists -> ON cds.artistID = artists.artistID WHERE (genres.genre = 'Pop'); ---------------------

MySQL changes table Storage EngineMySQL provides multiple database storage engines that store and extract data from MySQL databases. Different storage engines have different features. Sometimes you may need to convert an existing table storage engine into another storage eng