# dt-sql-parser-semantic-analyse-plugin

A [dt-sql-parser](https://github.com/DTStack/dt-sql-parser) plugin with semantic result. [Theory](https://github.com/Kijin-Seija/dt-sql-parser-analyse-demo).

## Installation

```
npm install dt-sql-parser-semantic-analyse-plugin
```

## Quick Usage

```typescript
const myPlugin = new DtSqlParserSemAnalysePlugin()
const sql = 'SELECT a| FROM t'
const caretColumn = sql.indexOf('|') + 1
const result = myPlugin.parse(sql.replace('|', ''), { lineNumber: 1, columnNumber: caretColumn })
console.log(result)
```

This will use a postgresql Parser and build-in rules/preprocessors

## Add a Rule Chain

```typescript
import { PostgresSQL } from 'dt-sql-parser'
import { PostgreSQLParser } from 'dt-sql-parser/dist/lib/pgsql/PostgreSQLParser'

const myPlugin = new DtSqlParserSemAnalysePlugin({
  parse: {
    parser: new PostgresSQL()
    stmts: [
      'selectstmt'
    ],
    entities: [
      'column_name'
    ],
    rules: {
      'select_columns': [
        PostgreSQLParser.RULE_insertstmt,
        PostgreSQLParser.RULE_column_name
      ]      
    }
  }
})
const sql = 'SELECT a| FROM t'
const caretColumn = sql.indexOf('|') + 1
const result = myPlugin.parse(sql.replace('|', ''), { lineNumber: 1, columnNumber: caretColumn })
console.log(result)
```

**Notice: A rule must start with a/an statement/entity and stop with an entity. You should add a node keywords(keyword is in your parser with format: `RULE_[keyword]`) into stmts/entities before using it.**

## Add a preprocessor

```typescript
const myPlugin = new DtSqlParserSemAnalysePlugin({
  preprocessor: [
    (sql) => sql.toUpperCase()
})
```