💡 Changed the lock_key column constraint to primary key

migrations/add-primary-key-to-lock-table.js

@@ -0,0 +1,54 @@
+const debug = require('debug')('knex-migrator:lock-table');
+
+/**
+ * Checks if primary key index exists in a table over the given columns.
+ */
+function hasPrimaryKey(tableName, knex) {
+    const client = knex.client.config.client;
+
+    if (client === 'mysql') {
+        const dbName = knex.client.config.connection.database;
+        return knex.raw(`
+                SELECT CONSTRAINT_NAME
+                FROM information_schema.TABLE_CONSTRAINTS
+                WHERE CONSTRAINT_SCHEMA=:dbName
+                AND TABLE_NAME=:tableName
+                AND CONSTRAINT_TYPE='PRIMARY KEY'`, {dbName, tableName})
+            .then(([rawConstraints]) => {
+                return rawConstraints.length > 0;
+            });
+    } else {
+        return knex.raw(`PRAGMA index_list('${tableName}');`)
+            .then((rawConstraints) => {
+                const tablePrimaryKey = rawConstraints.find(c => c.origin === 'pk');
+                return tablePrimaryKey;
+            });
+    }
+}
+
+/**
+ * Adds an primary key index to a table over the given columns.
+ */
+function addPrimaryKey(tableName, columns, knex) {
+    return hasPrimaryKey(tableName, knex)
+        .then((hasUniqueConstraint) => {
+            if (!hasUniqueConstraint) {
+                debug(`Adding primary key constraint for: ${columns} in table ${tableName}`);
+                return knex.schema.table(tableName, function (table) {
+                    table.primary(columns);
+                });
+            } else {
+                debug(`Primary key constraint for: ${columns} already exists for table: ${tableName}`);
+            }
+        });
+}
+
+/**
+ * @description Private helper to create add a primary key to the migration lock table. The helper is called as part of `runDatabaseUpgrades`.
+ * @returns {*}
+ */
+module.exports.up = function (connection) {
+    debug('Add primary key to the lock table.');
+
+    return addPrimaryKey('migrations_lock', 'lock_key', connection);
+};

migrations/index.js

@@ -1,6 +1,7 @@
 const lockTable = require('./lock-table');
 const fieldLength = require('./field-length');
 const useIndex = require('./use-index');
+const addPKToLockTable = require('./add-primary-key-to-lock-table');
 
 /**
  * @description Helper to run database migrations for the database tables, which knex-migrator is using.
@@ -11,5 +12,6 @@ module.exports.run = function (connection) {
     return Promise.resolve()
         .then(() => lockTable.up(connection))
         .then(() => fieldLength.up(connection))
-        .then(() => useIndex.up(connection));
+        .then(() => useIndex.up(connection))
+        .then(() => addPKToLockTable.up(connection));
 };

migrations/lock-table.js

@@ -15,7 +15,7 @@ module.exports.up = function (connection) {
             }
 
             return connection.schema.createTable('migrations_lock', function (table) {
-                table.string('lock_key', 191).nullable(false).unique();
+                table.string('lock_key', 191).nullable(false).primary();
                 table.boolean('locked').default(0);
                 table.dateTime('acquired_at').nullable();
                 table.dateTime('released_at').nullable();

test/functional/functional_spec.js

@@ -798,5 +798,23 @@ _.each(['default', 'migrateInit'], function (initMethod) {
                     });
             });
         });
+
+        it('change current version', function () {
+            knexMigrator.currentVersion = '1.4';
+            if (config.get('database:client') === 'sqlite3') {
+                return connection.raw(`PRAGMA index_list('migrations_lock');`).then((indexes) => {
+                    indexes.filter(index => index.origin === 'pk').length.should.eql(1);
+                });
+            } else {
+                return connection.raw(`
+                SELECT CONSTRAINT_NAME
+                FROM information_schema.TABLE_CONSTRAINTS
+                WHERE TABLE_NAME=:tableName
+                AND CONSTRAINT_TYPE='PRIMARY KEY'`, {tableName: 'migrations_lock'})
+                    .then(([rawConstraints]) => {
+                        rawConstraints.length.should.eql(1);
+                    });
+            }
+        });
     });
 });