D1 client API

D1 is compatible with most SQLite’s SQL convention since it leverages SQLite’s query engine. D1 client API allows you to interact with a D1 database from within a Worker.

​​ Prepared and static statements

D1 client API supports prepared and static statements. Best practice is to use prepared statements which are precompiled objects used by the database to run the SQL. This is because prepared statements lead to overall faster execution and prevent SQL injection attacks.

Below is an example of a prepared statement:

However, if you still choose to use a static statement you can use the following as an example:

​​ Parameter binding

D1 follows the SQLite convention Open external link for prepared statements parameter binding. Currently, D1 only supports Ordered (?NNNN) and Anonymous (?) parameters. In the future, D1 will support named parameters as well.

To bind a parameter, use the stmt.bind() method.

​​ Order and anonymous examples:

​​ Type conversion

D1 automatically converts supported JavaScript (including TypeScript) types passed as parameters via the client API to their associated D1 types. The type conversion is as follows:

¹ D1 supports 64-bit signed INTEGER values internally, however BigInts Open external link are not currently supported in the API yet. JavaScript integers are safe up to Number.MAX_SAFE_INTEGER Open external link .

² Booleans will be cast to an INTEGER type where 1 is TRUE and 0 is FALSE.

​​ Return object

The methods stmt.all() and db.batch() return a typed D1Result object that contains the results (if applicable), the success status, and a meta object with the internal duration of the operation in milliseconds.

Example:

The db.exec() method returns a D1ExecResult object:

​​ Query statement methods

D1 client API supports the following query statement methods for querying against a D1 database:

• await stmt.all()
• await stmt.raw()
• await stmt.first( [column] )
• await stmt.run()
• await db.dump()
• await db.exec()

​​ await stmt.all()

Returns all rows as an array of objects, with each result row represented as an object on the results property of the D1Result type.

When joining tables with identical column names, only the leftmost column will be included in the row object. Use stmt.raw() to return all rows as an array of arrays.

​​ await stmt.raw()

Returns results as an array of arrays, with each row represented by an array. The return type is an array of arrays, and does not include query metadata.

Column names are not included in the result set by default. To include column names as the first row of the result array, set .raw({columnNames: true}).

​​ await stmt.first([column])

Returns the first row of the results. This does not return metadata like the other methods. Instead, it returns the object directly.

Get a specific column from the first row:

Get all the columns from the first row:

If the query returns no rows, then first() will return null.

If the query returns rows, but column does not exist, then first() will throw the D1_ERROR exception.

stmt.first() does not alter the SQL query. To improve performance, consider appending LIMIT 1 to your statement.

​​ await stmt.run()

Runs the query (or queries), but returns no results. Instead, run() returns the metrics only. Useful for write operations like UPDATE, DELETE or INSERT.

​​ await db.dump()

Dumps the entire D1 database to an SQLite compatible file inside an ArrayBuffer.

​​ await db.exec()

Executes one or more queries directly without prepared statements or parameters binding. This method can have poorer performance (prepared statements can be reused in some cases) and, more importantly, is less safe. Only use this method for maintenance and one-shot tasks (for example, migration jobs). The input can be one or multiple queries separated by \n.

If an error occurs, an exception is thrown with the query and error messages, execution stops and further statements are not executed. Refer to Errors to learn more.

​​ TypeScript support

D1 client API is fully-typed via the @cloudflare/workers-types package, and also supports generic types Open external link as part of its TypeScript API. A generic type allows you to provide an optional type parameter so that a function understands the type of the data it is handling.

When using the query statement methods stmt.all(), stmt.raw() and stmt.first(), you can provide a type representing each database row. D1’s API will return the result object with the correct type.

For example, providing an OrderRow type as a type parameter to stmt.all() will return a typed Array<OrderRow> object instead of the default Record<string, unknown> type:

​​ Reuse prepared statements

Prepared statements can be reused with new bindings:

​​ Search with LIKE

Perform a search using SQL’s LIKE operator:

​​ Batch statements

Batching sends multiple SQL statements inside a single call to the database. This can have a huge performance impact as it reduces latency from network round trips to D1. D1 operates in auto-commit. Our implementation guarantees that each statement in the list will execute and commit, sequentially, non-concurrently.

Batched statements are SQL transactions Open external link . If a statement in the sequence fails, then an error is returned for that specific statement, and it aborts or rolls back the entire sequence.

​​ db.batch()

To send batch statements, provide batch() a list of prepared statements and get the results in the same order.

You can construct batches reusing the same prepared statement:

​​ PRAGMA statements

D1 supports the following SQLite PRAGMA Open external link statements:

Other PRAGMAs are disabled because of D1 implementation specifics.

​​ Errors

The stmt. and db. methods will throw an Error object Open external link whenever an error occurs.

To capture exceptions, log the Error.message value. For example, the code below has a query with an invalid keyword - INSERTZ instead of INSERT:

The code above would throw the following error message:

​​ Error list

D1 will return the following error constants, in addition to the extended (detailed) error message: