CODEWITHSUNDEEP
androidandroid-roomandroid-architecture-components
Raicky Derwent
Raicky Derwent

Reputation: 393

java.lang.IllegalStateException: Migration didn't properly handle table

How do you migrate an empty field type to text in Room ?

Right now I'm facing this issue :

java.lang.IllegalStateException: Migration didn't properly handle data_table

Expected: TableInfo{name='data_table', columns= url=Column{name='url', type='TEXT', notNull=false, primaryKeyPosition=0}.....

Found: TableInfo{name='data_table', columns= url=Column{name='url', type='', notNull=false, primaryKeyPosition=0}.....

I've tried using the UNDEFINED typeAffinity, but that has no effect.

Upvotes: 2

Views: 4301

Answers (1)

littlebear333
littlebear333

Reputation: 760

The problem is when creating the table, the creator did't indicate the column explicitly. There are two ways to be chosen to solve the problem.

  1. You can create a new DB during migration and copy all the old data into the new one. Like this.

    static final Migration MIGRATION_1_2 = new Migration(1, 2) {
    @Override
    public void migrate(SupportSQLiteDatabase database) {
        // Create the new table
        database.execSQL(
                "CREATE TABLE data_table_new (url TEXT");
        // Copy the data
        database.execSQL(
                "INSERT INTO data_table_new url SELECT url FROM data_table");
        // Remove the old table
        database.execSQL("DROP TABLE data_table");
        // Change the table name to the correct one
        database.execSQL("ALTER TABLE data_table_new RENAME TO data_table");
    }
};

But it is inefficient when working with large db. So I use the second way.

2 You migrate the table to new table with explicit column type with your favourite db manager or terminal. Then put the new db into your project.

Upvotes: 1

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