1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
import { _ISchema, _Transaction, _ISequence, _IStatementExecutor, _IStatement, asSeq, asIndex, _INamedIndex, _ITable, asTable } from '../../interfaces-private.ts';import { DropStatement } from 'https://deno.land/x/pgsql_ast_parser@12.0.1/mod.ts';import { ExecHelper } from '../exec-utils.ts';import { ignore, notNil } from '../../utils.ts';
export class DropTable extends ExecHelper implements _IStatementExecutor {    private tables: _ITable[];    private cascade: boolean;

    constructor({ schema }: _IStatement, statement: DropStatement) {        super(statement);
        this.tables = notNil(statement.names.map(x => asTable(schema.getObject(x, {            nullIfNotFound: statement.ifExists,        }))));
        this.cascade = statement.cascade === 'cascade';
        if (!this.tables.length) {            ignore(statement);        }    }
    execute(t: _Transaction) {        // commit pending data before making changes        //  (because it does not support further rollbacks)        t = t.fullCommit();
        // drop table        for (const table of this.tables) {            table.drop(t, this.cascade);        }
        // new implicit transaction        t = t.fork();
        return this.noData(t, 'DROP');    }}