This chapter describes the syntax of DistSQL in detail, and introduces use of DistSQL with practical examples.

Syntax Rule

In DistSQL statement, except for keywords, the input format of other elements shall conform to the following rules.

Identifier

  1. The identifier represents an object in the SQL statement, including:
  • database name
  • table name
  • column name
  • index name
  • resource name
  • rule name
  • algorithm name
  1. The allowed characters in the identifier are: [a-z, A-Z, 0-9, _] (letters, numbers, underscores) and should start with a letter.
  2. When keywords or special characters appear in the identifier, use the backticks (`).

Literal

Types of literals include:

  • string: enclosed in single quotes (‘) or double quotes (“)
  • int: it is generally a positive integer, such as 0-9;

Note: some DistSQL syntax allows negative values. In this case, a negative sign (-) can be added before the number, such as -1.

  • boolean, containing only true & false. Case insensitive.

Special Instructions

  • The "" must be used to mark the algorithm type name when specifying a user-defined algorithm type name, for example, NAME="AlgorithmTypeName"

  • The "" is not necessary when specifying a ShardingSphere Built-in algorithm type name, for example, NAME=HASH_MOD