检查 Laravel 迁移文件中是否存在列
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Check If a Column Exists in Laravel Migration File
提问by Md.Sukel Ali
Already I have a table name table_one.Now I want to add two more columns to it. Everything works fine so far. But in my method, I want to check a column exists or not in my table like dropIfExists('table').
我已经有了一个表名table_one.现在我想再向其中添加两列。到目前为止一切正常。但是在我的方法中，我想检查表中是否存在一列，例如dropIfExists('table').
/**
* Run the migrations.
*
* @return void
*/
public function up()
{
Schema::table('table_one', function (Blueprint $table) {
$table->string('column_one')->nullable();
$table->string('column_two')->nullable();
});
}
/**
* Reverse the migrations.
*
* @return void
*/
public function down()
{
Schema::table('table_one', function (Blueprint $table) {
// in here i want to check column_one and column_two exists or not
$table->dropColumn('column_one');
$table->dropColumn('column_two');
});
}
回答by Ismoil Shifoev
You need something just like this
你需要这样的东西
public function down()
{
if (Schema::hasColumn('users', 'phone'))
{
Schema::table('users', function (Blueprint $table)
{
$table->dropColumn('phone');
});
}
}
回答by PHP_only
Just break the schema up into two calls
只需将架构分成两个调用
public function up()
{
Schema::table('table_one', function (Blueprint $table) {
$table->dropColumn(['column_one', 'column_two']);
});
Schema::table('table_one', function (Blueprint $table) {
$table->string('column_one')->nullable();
$table->string('column_two')->nullable();
});
}
