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import { _ITable, _Transaction, IValue, _Explainer, _ISchema, asTable, _ISelection, _IIndex, _IStatement } from '../../interfaces-private.ts';import { DeleteStatement } from 'https://deno.land/x/pgsql_ast_parser@12.0.1/mod.ts';import { MutationDataSourceBase } from './mutation-base.ts';import { buildCtx } from '../../parser/context.ts';
export class Deletion extends MutationDataSourceBase<any> {

    constructor(ast: DeleteStatement) {        const { schema } = buildCtx();        const table = asTable(schema.getObject(ast.from));        const mutatedSel = table            .selection            .filter(ast.where);
        super(table, mutatedSel, ast);    }
    protected performMutation(t: _Transaction): any[] {        // perform deletion        const rows = [];        for (const item of this.mutatedSel.enumerate(t)) {            this.table.delete(t, item);            rows.push(item);        }        return rows;    }}