238 lines
6.4 KiB
JavaScript
238 lines
6.4 KiB
JavaScript
// Простенький "селект билдер" по мотивам MediaWiki-овского, успешно юзаю подобный в PHP уже лет 8
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// (c) Виталий Филиппов, 2019
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// В PHP, правда, прикольнее - там в массиве можно смешивать строковые и численные ключи,
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// благодаря чему можно писать $where = [ 't1.a=t2.a', 't2.b' => [ 1, 2, 3 ] ]
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const pg = require('pg');
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// Сраный node-postgres конвертирует даты в Date и портит таймзону
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const DATATYPE_DATE = 1082;
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pg.types.setTypeParser(DATATYPE_DATE, function(val)
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{
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return val === null ? null : val;
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});
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let pg_escape;
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const MS_HASH = 0;
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const MS_LIST = 1;
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const MS_ROW = 2;
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const MS_COL = 4;
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const MS_VALUE = 6;
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function selectBuilder(tables, fields, where, options)
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{
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let sql = 'SELECT ', bind = [];
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if (fields instanceof Array)
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{
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sql += fields.join(', ');
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}
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else if (typeof fields == 'string')
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{
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sql += fields;
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}
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else if (typeof fields == 'object')
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{
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sql += Object.keys(fields).map(k => fields[k]+' AS '+k).join(', ');
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}
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else
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{
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throw new Error('fields = '+fields+' is invalid');
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}
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sql += ' FROM ';
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let first = true;
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let moreWhere = null;
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tables = typeof tables == 'string' ? { t: tables } : tables;
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for (const k in tables)
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{
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if (first)
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{
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if (typeof tables[k] != 'string')
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{
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// Бывает удобно указывать WHERE как условие "JOIN" первой таблицы
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sql += tables[k][1] + ' ' + k;
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moreWhere = tables[k][2];
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}
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else
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{
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sql += tables[k] + ' ' + k;
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}
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first = false;
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}
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else if (typeof tables[k] == 'string')
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{
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sql += ' INNER JOIN '+tables[k]+' '+k+' ON 1=1';
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}
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else
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{
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const on = whereBuilder(tables[k][2]);
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sql += ' ' + tables[k][0].toUpperCase() + ' JOIN ' + tables[k][1] + ' ' + k + ' ON ' + (on[0] || '1=1');
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bind.push.apply(bind, on[1]);
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}
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}
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const w = whereBuilder(where);
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sql += ' WHERE '+(w[0] || '1=1');
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bind.push.apply(bind, w[1]);
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if (moreWhere)
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{
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moreWhere = whereBuilder(moreWhere);
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if (moreWhere[0])
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{
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sql += ' AND '+moreWhere[0];
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bind.push.apply(bind, moreWhere[1]);
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}
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}
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options = options||{};
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if (options['GROUP BY'] || options.group_by)
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{
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let group = options['GROUP BY'] || options.group_by;
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group = group instanceof Array ? group : [ group ];
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sql += ' GROUP BY '+group.join(', ');
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}
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if (options['ORDER BY'] || options.order_by)
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{
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let order = options['ORDER BY'] || options.order_by;
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order = order instanceof Array ? order : [ order ];
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sql += ' ORDER BY '+order.join(', ');
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}
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if (options.LIMIT || options.limit)
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{
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sql += ' LIMIT '+((options.LIMIT || options.limit) | 0);
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}
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if (options.OFFSET || options.offset)
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{
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sql += ' LIMIT '+((options.OFFSET || options.offset) | 0);
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}
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return [ sql, bind ];
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}
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function whereOrSetBuilder(fields, where)
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{
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if (typeof fields == 'string')
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return [ fields, [] ];
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const w = [], bind = [];
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for (const k in fields)
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{
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let v = fields[k];
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if (k.indexOf('?') >= 0)
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{
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if (!(v instanceof Array))
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v = [ v ];
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w.push(k);
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bind.push.apply(bind, v);
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}
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else if (/^\d+$/.exec(k))
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{
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if (v instanceof Array)
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{
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w.push(v[0]);
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bind.push.apply(bind, v.slice(1));
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}
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else
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{
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w.push(v);
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}
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}
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else if (v != null || v instanceof Array && v.length)
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{
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v = v instanceof Array ? v : [ v ];
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w.push(v.length == 1 ? k + ' = ?' : k + ' in (' + v.map(() => '?').join(', ') + ')');
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bind.push.apply(bind, v);
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}
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}
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if (!where)
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return [ w.join(', '), bind ];
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return [ w.length ? '('+w.join(') and (')+')' : '', bind ];
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}
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function whereBuilder(where)
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{
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return whereOrSetBuilder(where, true);
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}
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function _positional(sql)
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{
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let i = 0;
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sql = sql.replace(/\?/g, () => '$'+(++i));
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return sql;
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}
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function _inline(sql, bind)
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{
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if (!pg_escape)
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{
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pg_escape = require('pg-escape');
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}
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let i = 0;
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sql = sql.replace(/\?/g, () => '\''+pg_escape.string(bind[i++])+'\'');
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return sql;
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}
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// dbh = node-postgres.Client
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async function select(dbh, tables, fields, where, options, format)
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{
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let [ sql, bind ] = selectBuilder(tables, fields, where, options);
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//console.log(_inline(sql, bind));
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let data = await dbh.query(_positional(sql), bind);
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if ((format & MS_LIST) || (format & MS_COL))
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data = data.rows.map(r => Object.values(r));
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else
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data = data.rows;
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if (format & MS_ROW)
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data = data[0];
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if (data && (format & MS_COL))
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data = data[0];
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return data;
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}
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async function insert(dbh, table, rows)
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{
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if (!(rows instanceof Array))
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{
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rows = [ rows ];
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}
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if (!rows.length)
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{
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return null;
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}
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const keys = Object.keys(rows[0]);
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let sql = 'insert into '+table+' ('+keys.join(', ')+') values ';
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const bind = [];
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let i = 0;
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for (const row of rows)
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{
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sql += (i > 0 ? ', (' : '(') + keys.map(() => '$'+(++i)).join(', ')+')';
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bind.push.apply(bind, keys.map(k => row[k]));
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}
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return await dbh.query(sql, bind);
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}
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async function _delete(dbh, table, where)
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{
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const w = whereBuilder(where);
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const sql = 'DELETE FROM '+table+' WHERE '+(w[0] || '1=1');
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return await dbh.execute(_positional(sql), w[1]);
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}
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async function update(dbh, table, set, where)
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{
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set = whereOrSetBuilder(set, false);
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where = whereOrSetBuilder(where, true)
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const sql = 'UPDATE '+table+' SET '+set[0]+' WHERE '+(where[0] || '1=1');
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const bind = [ ...set[1], ...where[1] ];
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return await dbh.execute(_positional(sql), bind);
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}
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module.exports = {
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select,
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insert,
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delete: _delete,
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update,
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MS_HASH,
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MS_LIST,
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MS_ROW,
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MS_COL,
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MS_VALUE,
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};
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