lava-oushudb-dt-sql-parser/README.md

dt-sql-parser

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dt-sql-parser is a SQL Parser project built with ANTLR4, and it's mainly for the BigData domain. The ANTLR4 generated the basic Parser, Visitor, and Listener, so it's easy to complete the syntax validation, tokenizer, traverse the AST, and so on features.

Besides, it provides some helper methods, like split SQL, and Auto-Complete.

Supported SQL:

• Generic SQL (MySQL)
• Flink SQL
• Spark SQL
• Hive SQL
• PL/SQL
• PostgreSQL
• Trino SQL

Supported helper methods

SQL Type	SQL Split	Auto-Complete
Generic SQL	WIP	WIP
Flink SQL	✅	✅
Spark SQL	✅	✅
Hive SQL	✅	✅
PL/SQL	WIP	WIP
Postgre SQL	WIP	WIP
Trino SQL	WIP	WIP

Tips: This project is the default for Javascript language, also you can try to compile it to other languages if you need.

Integrating SQL Parser with Monaco Editor

We have provided a monaco-sql-languages package, you can integrate with monaco-editor easily.

Installation

# use npm
npm i dt-sql-parser --save

# use yarn
yarn add dt-sql-parser

Usage

Before you get started, you need to understand the basics of how to use it. dt-sql-parser provides SQL parser classes for different types of supported SQL:

import { GenericSQL, FlinkSQL, SparkSQL, HiveSQL, PLSQL, PostgresSQL, TrinoSQL } from 'dt-sql-parser';

Before using syntax validation, autocompletion, and other method, you need to instantiate the Parser of the corresponding SQL type, taking GenericSQL as an example:

const parser = new GenericSQL();

The usage examples below will use GenericSQL, and Parser for other SQL types will be used in the same way as GenericSQL.

Syntax Validation

import GenericSQL from 'dt-sql-parser/dist/parser/generic';

const parser = new GenericSQL();

const correctSql = 'select id,name from user1;';
const errors = parser.validate(correctSql);
console.log(errors); 

Output:

/*
[]
*/

Validate failed:

const incorrectSql = 'selec id,name from user1;'
const errors = parser.validate(incorrectSql);
console.log(errors); 

Output:

/*
[
    {
        endCol: 5,
        endLine: 1,
        startCol: 0,
        startLine: 1,
        message: "mismatched input 'SELEC' expecting {<EOF>, 'ALTER', 'ANALYZE', 'CALL', 'CHANGE', 'CHECK', 'CREATE', 'DELETE', 'DESC', 'DESCRIBE', 'DROP', 'EXPLAIN', 'GET', 'GRANT', 'INSERT', 'KILL', 'LOAD', 'LOCK', 'OPTIMIZE', 'PURGE', 'RELEASE', 'RENAME', 'REPLACE', 'RESIGNAL', 'REVOKE', 'SELECT', 'SET', 'SHOW', 'SIGNAL', 'UNLOCK', 'UPDATE', 'USE', 'BEGIN', 'BINLOG', 'CACHE', 'CHECKSUM', 'COMMIT', 'DEALLOCATE', 'DO', 'FLUSH', 'HANDLER', 'HELP', 'INSTALL', 'PREPARE', 'REPAIR', 'RESET', 'ROLLBACK', 'SAVEPOINT', 'START', 'STOP', 'TRUNCATE', 'UNINSTALL', 'XA', 'EXECUTE', 'SHUTDOWN', '--', '(', ';'}"
    }
]
*/

We instanced a Parser object, and use the validate method to check the SQL syntax, if failed returns an array object includes error message.

Tokenizer

Get all tokens by the Parser:

import GenericSQL from 'dt-sql-parser/dist/parser/generic';

const parser = new GenericSQL()
const sql = 'select id,name,sex from user1;'
const tokens = parser.getAllTokens(sql)
console.log(tokens)
/*
[
    {
        channel: 0
        column: 0
        line: 1
        source: [SqlLexer, InputStream]
        start: 0
        stop: 5
        tokenIndex: -1
        type: 137
        _text: null
    },
    ...
]
*/

Visitor

Traverse the tree node by the Visitor:

import GenericSQL from 'dt-sql-parser/dist/parser/generic';
import { SqlParserVisitor } from 'dt-sql-parser/dist/parser/generic/SqlParserVisitor';

const parser = new GenericSQL()
const sql = `select id,name from user1;`
// parseTree
const tree = parser.parse(sql)
class MyVisitor extends SqlParserVisitor {
    // overwrite visitTableName
    visitTableName(ctx) {
        let tableName = ctx.getText().toLowerCase()
        console.log('TableName', tableName)
    }
    // overwrite visitSelectElements
    visitSelectElements(ctx) {
        let selectElements = ctx.getText().toLowerCase()
        console.log('SelectElements', selectElements)
    }
}
const visitor = new MyVisitor()
visitor.visit(tree)

/*
SelectElements id,name
TableName user1
*/

Tips: The node's method name can be found in the Visitor file under the corresponding SQL directory

Listener

Access the specified node in the AST by the Listener

import GenericSQL from 'dt-sql-parser/dist/parser/generic';
import { SqlParserListener } from 'dt-sql-parser/dist/parser/generic/SqlParserListener';

const parser = new GenericSQL();
const sql = 'select id,name from user1;'
// parseTree
const tree = parser.parse(sql)
class MyListener extends SqlParserListener {
    enterTableName(ctx) {
        let tableName = ctx.getText().toLowerCase()
        console.log('TableName', tableName)
    }
    enterSelectElements(ctx) {
        let selectElements = ctx.getText().toLowerCase()
        console.log('SelectElements', selectElements)
    }
}
const listenTableName = new MyListener();
parser.listen(listenTableName, tree);

/*
SelectElements id,name
TableName user1
*/

Tips: The node's method name can be found in the Listener file under the corresponding SQL directory

Split sql by statement

Take FlinkSQL as an example:

import { FlinkSQL } from 'dt-sql-parser';
const parser = new FlinkSQL();
const sql = 'SHOW TABLES;\nSELECT * FROM tb;';
const sqlSlices = parser.splitSQLByStatement(sql);
console.log(sqlSlices)

/*
[
    {
    startIndex: 0,
    endIndex: 11,
    startLine: 1,
    endLine: 1,
    startColumn: 1,
    endColumn: 12,
    text: 'SHOW TABLES;'
    },
    {
    startIndex: 13,
    endIndex: 29,
    startLine: 2,
    endLine: 2,
    startColumn: 1,
    endColumn: 17,
    text: 'SELECT * FROM tb;'
    }
]
*/

Auto Complete

Get the autocomplete information in the specified position of sql, using FlinkSQL as an example:

Call the getSuggestionAtCaretPosition method, passing in the SQL content and the row and column numbers of the position that need to be autocompleted.

• Get a list of keyword candidates

  import { FlinkSQL } from 'dt-sql-parser';
  const parser = new FlinkSQL();
  const sql = 'CREATE ';
  const pos = { lineNumber: 1, column: 16 }; // the end position
  const keywords = parser.getSuggestionAtCaretPosition(sql, pos)?.keywords;
  console.log(keywords);
  
  /*
  [ 'CATALOG', 'FUNCTION', 'TEMPORARY', 'VIEW', 'DATABASE', 'TABLE' ] 
  */ 
  

• Gets syntax-related autocompletion information

  const parser = new FlinkSQL();
  const sql = 'SELECT * FROM tb';
  const pos = { lineNumber: 1, column: 16 }; // after 'tb'
  const syntaxSuggestions = parser.getSuggestionAtCaretPosition(sql, pos)?.syntax;
  console.log(syntaxSuggestions);
  
  /*
  [
    {
      syntaxContextType: 'table',
      wordRanges: [
        {
          text: 'tb',
          startIndex: 14,
          stopIndex: 15,
          line: 1,
          startColumn: 15,
          stopColumn: 16
        }
      ]
    },
    {
      syntaxContextType: 'view',
      wordRanges: [
        {
          text: 'tb',
          startIndex: 14,
          stopIndex: 15,
          line: 1,
          startColumn: 15,
          stopColumn: 16
        }
      ]
    }
  ]
  */
  

Syntax-related autocomplete information returns an array, and each item in the array represents what syntax can be filled in at that position, such as the output result in the above example represents that the position can be filled in table name or view name. The syntaxContextType is a syntax type that can be completed, and wordRanges is what has been filled in.

Other API

• createLexer Create an instance of Antlr4 Lexer and return;
• createParser Create an instance of Antlr4 parser and return;
• parse Parses the input SQL and returns the parse tree;

License

MIT