Change or rename a column name without losing data with Entity Framework Core 2.0

Question

I realised that I had spelt one of my column headers incorrectly so I changed it in the model and created a new migration to update it into the database. All worked perfectly un

Answer 1

migrationBuilder.RenameColumn usually works fine but sometimes you have to handle indexes as well.

migrationBuilder.RenameColumn(name: "Identifier", table: "Questions", newName: "ChangedIdentifier", schema: "dbo");

Example error message when updating database:

Microsoft.Data.SqlClient.SqlException (0x80131904): The index 'IX_Questions_Identifier' is dependent on column 'Identifier'.

The index 'IX_Questions_Identifier' is dependent on column 'Identifier'.

RENAME COLUMN Identifier failed because one or more objects access this column.

In this case you have to do the rename like this:

migrationBuilder.DropIndex(
    name: "IX_Questions_Identifier",
    table: "Questions");

migrationBuilder.RenameColumn(name: "Identifier", table: "Questions", newName: "ChangedIdentifier", schema: "dbo");

migrationBuilder.CreateIndex(
    name: "IX_Questions_ChangedIdentifier",
    table: "Questions",
    column: "ChangedIdentifier",
    unique: true,
    filter: "[ChangedIdentifier] IS NOT NULL");