At a high-level, queries operate on collections rather than individual documents. Filter, search, and retrieve specific information based on various criteria using Boolean operators, equal and unequal operators, comparison operators, and match operators. 

This article includes an overview of operators and path navigations for building advanced queries in your app, along with real-world examples.

For related information, see the Platform Manual:

When a field property is a boolean data type, use explicit true-false values.

For example, to find documents with an "isDeleted" boolean property set to "true":

To find documents with an "isDeleted" boolean property set to "false":

To find documents that match a given key-value pair, use the equal operator. Where you specify the key and the number or string value you want to match separated by ==.

For example, to find documents that have a title equal to "Harry Potter":

If, instead of finding documents that match, you want to find documents that do not match a given key-value pair, use the inequality operator. Where you specify the key and the value that you don’t want to match separated by !=.

For example, to find documents that are not of the title "Lord of the Rings":

Compare values in documents, set conditions, retrieve specific documents that meet your criteria, and make logical evaluations using the following operators in your query statements.

For example:

To find documents where age field property is less than or equal to the value of 18:

To find documents where the age field property is less than the value of 18:

To find documents where the age field property is greater than or equal to the value of 18:

To find documents where the age field property is greater than the value of 18:

Perform complex operations in a single executable by using compound operators. A compound operator is a combination of two or more operators in a single executable:

Similar to SQL AND statements, use && for a condition that evaluates to true only when all of its conditions are set to true.

For example, to find documents that have a theme field property equal to "Dark" and a name field property equal to "Light":

Similar to SQL OR statements, use || for a logical or predicate statement.

For example, to find documents that are "Tom" or "Arthur":

Similar to SQL NOT statements, use ! for logical not predicate statements:

For example, find documents that are neither "Hamilton" nor "Morten":

Use starts_with(property, test) to test if a field property with a string value starts with a test string.

For example, to find documents with a title field property that begins with "Lord":

Use ends_with(property, test) to test if a field property with a string value ends with a test string.

For example, to find documents with a title field property that ends with "Rings":

Use regex(property, test) to see if a field property with a string value passes a regular expression. For more information, see the official Mozilla Developer Network Docs (MDN) > Regular Expressions.

For example, to find documents containing only upper and lowercase letters, numbers, and underscores:

Use null to check for the existence of a value of a given field.

For example, to find documents with a color field property that has no value:

When handling collections of data that different peers may make concurrent updates to, first consider using an embedded map structure. If necessary, use an array.

The array type in Ditto is a CRDT and behaves differently than the primitive array type. For more information, see the Platform Manual > Data Types.

When parsing date and time strings, use the ISO-8601 standard format, as follows.

For more information, see Platform Manual > Using ISO-8601 for Date Strings.

If fields consist of alphanumeric characters or include underscores, use any of the following notations to navigate document properties.