What are query variables?
Query variables can be used in other query blocks or in a child node of the defining block. Query variables do not affect the semantics of the query at the point of definition. If a variable is defined, it must be used elsewhere in the query. A query variable is used by extracting the UIDs in it with uid(var-name) .
What is query variables in GraphQL?
Instead, GraphQL has a first-class way to factor dynamic values out of the query, and pass them as a separate dictionary. These values are called variables. When we start working with variables, we need to do three things: Replace the static value in the query with $variableName.
How do you add a query variable in GraphiQL?
The GraphiQL client allows you to create variables for use in your queries. To add a query variable, click the Query Variables pane and enter a JSON object that defines your variable. To use a variable in your query, prepend the $ character to your variable name and use it to replace the desired value.
What is useLazyQuery?
Manual execution with useLazyQuery The useLazyQuery hook is perfect for executing queries in response to events besides component rendering. Instead, it returns a query function in its result tuple that you call whenever you’re ready to execute the query.
What is GraphQL mutation?
Mutations allow you to modify server-side data, and it also returns an object based on the operation performed. It can be used to insert, update, or delete data. Dgraph automatically generates GraphQL mutations for each type that you define in your schema.
What is GraphQL fragment?
A GraphQL fragment is a piece of logic that can be shared between multiple queries and mutations. Here’s the declaration of a NameParts fragment that can be used with any Person object: fragment NameParts on Person { firstName lastName } Every fragment includes a subset of the fields that belong to its associated type.
How do you query in GraphiQL?
When the development server is running for one of your Gatsby sites, open GraphiQL at http://localhost:8000/___graphql and play with your data! Press Ctrl + Space (or use Shift + Space as an alternate keyboard shortcut) to bring up the autocomplete window and Ctrl + Enter to run the GraphQL query.
Who use GraphQL?
GraphQL is on the rise. Companies like Facebook, Netflix, Shopify or PayPal are using the data language and API technology to drive their products. Learn in this article, why you should be using it at your company.
What is GraphQL API?
GraphQL is a query language and server-side runtime for application programming interfaces (APIs) that prioritizes giving clients exactly the data they request and no more. As an alternative to REST, GraphQL lets developers construct requests that pull data from multiple data sources in a single API call.
What is GraphQL tag?
gql A JavaScript template literal tag that parses GraphQL query strings into the standard GraphQL AST. …
Which is an example of a query variable?
Query variables allow you to write a data source query that can return a list of metric names, tag values, or keys. For example, a query variable might return a list of server names, sensor IDs, or data centers. The variable values change as they dynamically fetch options with a data source query.
How do I get the variables into the query editor?
Next, we’ll get the variables table into the query editor. To bring the variables table into the query editor, we click any cell in the table and use the Data > From Table/Range command. It is immediately available in the query editor, as shown below.
Can you set a variable in a SQL query?
It’s Microsoft SQL Server in question. 🙂 Yes you can set variables within a query. Your syntax is actually quite close. Note: You cannot use the AS when assigning a field to a variable. You must ensure that all of the fields in the query are assigned to a variable, otherwise you will get the following error:
How to create a variable for a query expression?
Query expressions are different for each data source. For more information, refer to the documentation for your data source. Navigate to the dashboard you want to make a variable for and then click the Dashboard settings (gear) icon at the top of the page. On the Variables tab, click New. Enter a Name for your variable.