# Index and query documents This example shows how to create a [search index](https://redis.io/docs/latest/develop/interact/search-and-query/indexing) for [JSON](https://redis.io/docs/latest/develop/data-types/json) documents and run queries against the index. It then goes on to show the slight differences in the equivalent code for [hash](https://redis.io/docs/latest/develop/data-types/hashes) documents. From [v9.8.0](https://.com/redis/go-redis/releases/tag/v9.8.0) onwards, `go-redis` uses query dialect 2 by default. Redis query engine methods such as [`FTSearch()`](https://redis.io/docs/latest/commands/ft.search) will explicitly request this dialect, overriding the default set for the server. See [Query dialects](https://redis.io/docs/latest/develop/interact/search-and-query/advanced-concepts/dialects) for more information. ## Initialize Make sure that you have [Redis Open Source](https://redis.io/docs/latest/operate/oss_and_stack/) or another Redis server available. Also install the [`go-redis`](https://redis.io/docs/latest/develop/clients/go) client library if you haven't already done so. Add the following dependencies: ## Create data Create some test data to add to your database. The example data shown below is compatible with both JSON and hash objects. ## Add the index Connect to your Redis database. The code below shows the most basic connection but see [Connect to the server](https://redis.io/docs/latest/develop/clients/go/connect) to learn more about the available connection options. The connection options in the example specify [RESP2](https://redis.io/docs/latest/develop/reference/protocol-spec) in the `Protocol` field. We recommend that you use RESP2 for Redis query engine operations in `go-redis` because some of the response structures for the default RESP3 are currently incomplete and so you must handle the "raw" responses in your own code. If you do want to use RESP3, you should set the `UnstableResp3` option when you connect: ```go rdb := redis.NewClient(&redis.Options{ UnstableResp3: true, // Other options... }) ``` You must also access command results using the `RawResult()` and `RawVal()` methods rather than the usual `Result()` and `Val()`: ```go res1, err := client.FTSearchWithArgs( ctx, "txt", "foo bar", &redis.FTSearchOptions{}, ).RawResult() val1 := client.FTSearchWithArgs( ctx, "txt", "foo bar", &redis.FTSearchOptions{}, ).RawVal() ``` Use the code below to create a search index. The `FTCreateOptions` parameter enables indexing only for JSON objects where the key has a `user:` prefix. The [schema](https://redis.io/docs/latest/develop/interact/search-and-query/indexing) for the index has three fields for the user's name, age, and city. The `FieldName` field of the `FieldSchema` struct specifies a [JSON path](https://redis.io/docs/latest/develop/data-types/json/path) that identifies which data field to index. Use the `As` struct field to provide an alias for the JSON path expression. You can use the alias in queries as a short and intuitive way to refer to the expression, instead of typing it in full: ## Add the data Add the three sets of user data to the database as [JSON](https://redis.io/docs/latest/develop/data-types/json) objects. If you use keys with the `user:` prefix then Redis will index the objects automatically as you add them: ## Query the data You can now use the index to search the JSON objects. The [query](https://redis.io/docs/latest/develop/interact/search-and-query/query) below searches for objects that have the text "Paul" in any field and have an `age` value in the range 30 to 40: Specify query options to return only the `city` field: You can also use the same query with the `CountOnly` option enabled to get the number of documents found without returning the documents themselves. Use an [aggregation query](https://redis.io/docs/latest/develop/interact/search-and-query/query/aggregation) to count all users in each city. ## Differences with hash documents Indexing for hash documents is very similar to JSON indexing but you need to specify some slightly different options. When you create the schema for a hash index, you don't need to add aliases for the fields, since you use the basic names to access the fields anyway. Also, you must set `OnHash` to `true` in the `FTCreateOptions` object when you create the index. The code below shows these changes with a new index called `hash-idx:users`, which is otherwise the same as the `idx:users` index used for JSON documents in the previous examples. You use [`HSet()`](https://redis.io/docs/latest/commands/hset) to add the hash documents instead of [`JSONSet()`](https://redis.io/docs/latest/commands/json.set), but the same flat `userX` maps work equally well with either hash or JSON: The query commands work the same here for hash as they do for JSON (but the name of the hash index is different). The format of the result is almost the same except that the fields are returned directly in the `Document` object map of the result (for JSON, the fields are all enclosed in a string under the key "$"): ## More information See the [Redis query engine](https://redis.io/docs/latest/develop/interact/search-and-query) docs for a full description of all query features with examples.