EF Core设置Gin索引

EF Core中如何设置Gin索引?

https://stackoverflow.com/questions/54618858/can-jsonb-gin-indexes-be-specified-in-codefirst-entityframework-with-npgsql

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Since .ForNpgsqlHasMethod(“gin”) is obsolete, with EF Core 3.1 you can use this:

metaBuilder
    .HasIndex(x => x.DocumentNumber)
    .HasMethod("gin")
    .HasOperators("gin_trgm_ops");

and your migration will look like this:

migrationBuilder.CreateIndex(
    name: "IX_DocumentContentMeta_DocumentNumber",
    table: "DocumentContentMeta",
    column: "DocumentNumber")
    .Annotation("Npgsql:IndexMethod", "gin")
    .Annotation("Npgsql:IndexOperators", new[] { "gin_trgm_ops" });

---

Well, actually u can do it like this

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<Artist>()
       .HasIndex(a => new { a.Album })
       .ForNpgsqlHasMethod("gin");

    base.OnModelCreating(modelBuilder);
}

and when u run ef add migration, the sql query generated will be like:

CREATE INDEX ix_artist_album ON artist USING gin ("album");

Documentation in Npgsql: http://www.npgsql.org/efcore/modeling/indexes.html