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Use Constraints

DDM is compatible with the MySQL license and syntax, but the use of SQL statements is limited due to differences between distributed databases and single-node databases.

Unsupported SQL Statements

  • Triggers
  • Temporary tables
  • DO statement
  • Association with foreign keys
  • RESET statement
  • FLUSH statement
  • BINLOG statement
  • HANDLER statement
  • SHOW WARNINGS statement
  • Assignment operator :=
  • Operators less than (<), assignment (=), and more than (>)
  • Expression IS UNKNOWN
  • INSTALL and UNINSTALL PLUGIN statements
  • Cross-shard stored procedures and custom functions
  • Statements for modifying database names, table names, and sharding field names and types
  • Most of SHOW statements such as SHOW PROFILES and SHOW ERRORS
  • Table maintenance statements, including ANALYZE, CHECK, CHECKSUM, OPTIMIZE, and REPAIR TABLE
  • Statements for assigning a value to or querying variable session, for example, set @rowid=0;select @rowid:=@rowid+1,id from user
  • SQL statements that use -- or /*...*/ to comment out a single line or multiple lines of code
  • The result of the REPEAT function contains a maximum of 1,000,000 characters (in version 3.0.9 or later).

Permission Levels

Permission levels supported by DDM are as follows:

  • Global level (not supported)
  • Database level (supported)
  • Table level (supported)
  • Column level (not supported)
  • Subprogram level (not supported)
  • User level (supported)
Parent topic: SQL Syntax