अद्यतन करें:मैंने अब तक तीन परियोजनाओं में इसका उपयोग किया है, इसलिए मैंने एक npm मॉड्यूल बनाने का निर्णय लिया:https://www.npmjs.com/package/replace-enum-postgresql ।
मैंने ऐसा करने के लिए एक उपयोगिता बनाई है, आशा है कि यह आपके लिए मददगार साबित होगी।
utils/replace_enum.js
:
'use strict';
/**
* Since PostgreSQL still does not support remove values from an ENUM,
* the workaround is to create a new ENUM with the new values and use it
* to replace the other.
*
* @param {String} tableName
* @param {String} columnName
* @param {String} defaultValue
* @param {Array} newValues
* @param {Object} queryInterface
* @param {String} enumName - Optional.
*
* @return {Promise}
*/
module.exports = function replaceEnum({
tableName,
columnName,
defaultValue,
newValues,
queryInterface,
enumName = `enum_${tableName}_${columnName}`
}) {
const newEnumName = `${enumName}_new`;
return queryInterface.sequelize.transaction((t) => {
// Create a copy of the type
return queryInterface.sequelize.query(`
CREATE TYPE ${newEnumName}
AS ENUM ('${newValues.join('\', \'')}')
`, { transaction: t })
// Drop default value (ALTER COLUMN cannot cast default values)
.then(() => queryInterface.sequelize.query(`
ALTER TABLE ${tableName}
ALTER COLUMN ${columnName}
DROP DEFAULT
`, { transaction: t }))
// Change column type to the new ENUM TYPE
.then(() => queryInterface.sequelize.query(`
ALTER TABLE ${tableName}
ALTER COLUMN ${columnName}
TYPE ${newEnumName}
USING (${columnName}::text::${newEnumName})
`, { transaction: t }))
// Drop old ENUM
.then(() => queryInterface.sequelize.query(`
DROP TYPE ${enumName}
`, { transaction: t }))
// Rename new ENUM name
.then(() => queryInterface.sequelize.query(`
ALTER TYPE ${newEnumName}
RENAME TO ${enumName}
`, { transaction: t }))
.then(() => queryInterface.sequelize.query(`
ALTER TABLE ${tableName}
ALTER COLUMN ${columnName}
SET DEFAULT '${defaultValue}'::${enumName}
`, { transaction: t }));
});
}
और यह मेरा उदाहरण है माइग्रेशन:
'use strict';
const replaceEnum = require('./utils/replace_enum');
module.exports = {
up: (queryInterface, Sequelize) => {
return replaceEnum({
tableName: 'invoices',
columnName: 'state',
enumName: 'enum_invoices_state',
defaultValue: 'created',
newValues: ['archived', 'created', 'paid'],
queryInterface
});
},
down: (queryInterface, Sequelize) => {
return replaceEnum({
tableName: 'invoices',
columnName: 'state',
enumName: 'enum_invoices_state',
defaultValue: 'draft',
newValues: ['archived', 'draft', 'paid', 'sent'],
queryInterface
});
}
};