--- title: SQL for Mobile -- Differences from SQL for Server description: SQL++ differences between Couchbase Server and Couchbase Lite pubDate: 2026-08-17T09:53:44.266Z antora: editUrl: https://github.com/couchbase/docs-couchbase-lite/edit/release/3.3/modules/java/pages/query-n1ql-mobile-server-diffs.adoc xref: xref:3.3@couchbase-lite:java:query-n1ql-mobile-server-diffs.adoc[] --- [Consult the llms.txt file for a full list of contents](/llms.txt) [View original HTML](/couchbase-lite/3.3/java/query-n1ql-mobile-server-diffs.html) # SQL for Mobile -- Differences from SQL for Server > Description — _SQL++ differences between Couchbase Server and Couchbase Lite_ > Related Content — [Predictive Queries](querybuilder.md#lbl-predquery) | [Live Queries](query-live.md) | [Indexing](indexing.md) > [!IMPORTANT] > N1QL is Couchbase's implementation of the developing **SQL++** standard. As such the terms _N1QL_ and _SQL++_ are used interchangeably in Couchbase documentation unless explicitly stated otherwise. There are several minor but notable behavior differences between _SQL++ for Mobile_ queries and _SQL++ for Server_, as shown in [Table 1](#tbl-diffs). In some instances, if required, you can force SQL++ for Mobile to work in the same way as SQL++ for Server. This table compares Couchbase Server and Mobile instances: __Table 1\. SQL++ Query Comparison__ | | SQL++ Comparison | | | ---------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | Feature | SQL++ for Couchbase Server | SQL++ for Mobile | | Scopes and Collections | SELECT \*FROM \`travel-sample\`.inventory.airport | SELECT \*FROM inventory.airport | | Scopes and Collections | SELECT \*FROM \`travel-sample\`.inventory.airport | SELECT \*FROM inventory.airport | | USE KEYS | SELECT fname, email FROM tutorial USE KEYS \["dave", "ian"\]; | SELECT fname, email FROM tutorial WHERE meta().id IN ("dave", "ian"); | | ON KEYS | SELECT \*FROM \`user\` uJOIN orders o ON KEYS ARRAY s.order\_idFOR s IN u.order\_history END; | SELECT \* FROM user u, u.order\_history sJOIN orders o ON s.order\_id = meta(o).id; | | ON KEY | SELECT \*FROM \`user\` u JOIN orders o ON KEY o.user\_id FOR u; | SELECT \* FROM user uJOIN orders o ON meta(u).id = o.user\_id; | | NEST | SELECT \*FROM \`user\` u NEST orders orders ON KEYS ARRAY s.order\_id FOR s IN u.order\_history END; | NEST/UNNEST not supported | | LEFT OUTER NEST | SELECT \* FROM user uLEFT OUTER NEST orders ordersON KEYS ARRAY s.order\_id FOR s IN u.order\_history END; | NEST/UNNEST not supported | | ARRAY | ARRAY i FOR i IN \[1, 2\] END | (SELECT VALUE i FROM \[1, 2\] AS i) | | ARRAY FIRST | ARRAY FIRST arr | arr\[0\] | | LIMIT l OFFSET o | Allows OFFSET without LIMIT | Allows OFFSET without LIMIT | | UNION, INTERSECT, and EXCEPT | All three are supported (with ALL and DISTINCT variants) | Not supported | | OUTER JOIN | Both LEFT and RIGHT OUTER JOIN supported | Only LEFT OUTER JOIN supported (and necessary for query expressability) | | <, <=, =, etc. operators | Can compare either complex values or scalar values | Only scalar values may be compared | | ORDER BY | Result sequencing is based on specific rules described in [SQL++ (server) OrderBy clause](../../../server/current/n1ql/n1ql-language-reference/orderby.md) | Result sequencing is based on the SQLite ordering described in [SQLite select overview](https://sqlite.org/lang%5Fselect.html) The ordering of _Dictionary_ and _Array_ objects is based on binary ordering. | | SELECT DISTINCT | Supported | SELECT DISTINCT VALUE is supported when the returned values are scalars | | CREATE INDEX | Supported | Not Supported | | INSERT/UPSERT/DELETE | Supported | Not Supported | ## [](#boolean-logic-rules)Boolean Logic Rules | SQL++ for Couchbase Server | SQL++ for Mobile | | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Couchbase Server operates in the same way as Couchbase Lite, except: MISSING, NULL and FALSE are FALSE Numbers 0 is FALSE Empty strings, arrays, and objects are FALSE All other values are TRUE You can choose to use _Couchbase Server's SQL++ rules_ by using the TOBOOLEAN(expr) function to convert a value to its boolean value. | SQL++ for Mobile's boolean logic rules are based on SQLite's, so: TRUE is TRUE, and FALSE is FALSE Numbers 0 or 0.0 are FALSE Arrays and dictionaries are FALSE String and Blob are TRUE if the values are casted as a non-zero or FALSE if the values are casted as 0 or 0.0 — see: [SQLITE's CAST and Boolean expressions](https://sqlite.org/lang%5Fexpr.html)^ for more details) NULL is FALSE MISSING is MISSING | ### [](#logical-operations)Logical Operations In SQL++ for Mobile logical operations will return one of three possible values; `TRUE`, `FALSE`, or `MISSING`. Logical operations with the `MISSING` value could result in `TRUE` or `FALSE` if the result can be determined regardless of the missing value, otherwise the result will be `MISSING`. In SQL++ for Mobile — unlike SQL++ for Server — `NULL` is implicitly converted to `FALSE` before evaluating logical operations. [Table 2](#tbl-logops) summarizes the result of logical operations with different operand values and also shows where the Couchbase Server behavior differs. __Table 2\. Logical Operations Comparison__ | Operanda | SQL++ for Mobile | SQL++ for Server | | | | | | -------- | ---------------- | ---------------- | ---- | ----------- | -------- | -- | | b | a AND b | a OR b | b | a AND b | a OR b | | | TRUE | TRUE | TRUE | TRUE | \- | \- | \- | | FALSE | FALSE | TRUE | \- | \- | \- | | | NULL | FALSE | TRUE | \- | **NULL** | \- | | | MISSING | MISSING | TRUE | \- | \- | \- | | | FALSE | TRUE | FALSE | TRUE | \- | \- | \- | | FALSE | FALSE | FALSE | \- | \- | \- | | | NULL | FALSE | FALSE | \- | \- | **NULL** | | | MISSING | FALSE | MISSING | \- | \- | \- | | | NULL | TRUE | FALSE | TRUE | \- | **NULL** | \- | | FALSE | FALSE | FALSE | \- | \- | **NULL** | | | NULL | FALSE | FALSE | \- | **NULL** | **NULL** | | | MISSING | FALSE | MISSING | \- | **MISSING** | **NULL** | | | MISSING | TRUE | MISSING | TRUE | \- | \- | \- | | FALSE | FALSE | MISSING | \- | \- | \- | | | NULL | FALSE | MISSING | \- | **MISSING** | **NULL** | | | MISSING | MISSING | MISSING | \- | \- | \- | | ## [](#crud-operations)CRUD Operations SQL++ for Mobile only supports Read or Query operations. SQL++ for Server fully supports CRUD operation. ## [](#functions)Functions ### [](#division-operator)Division Operator | SQL++ for Server | SQL++ for Mobile | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | SQL++ for Server always performs float division regardless of the types of the operands. You can force this behavior in SQL++ for Mobile by using the DIV(x, y) function. | The operand types determine the division operation performed.If both are integers, integer division is used.If one is a floating number, then float division is used. | ### [](#round-function)Round Function | SQL++ for Server | SQL++ for Mobile | | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | SQL++ for Server ROUND() uses the _Rounding to Nearest Even_ convention (for example, ROUND(1.85) returns 1.8). You can force this behavior in Couchbase Lite by using the ROUND\_EVEN() function. | The ROUND() function returns a value to the given number of integer digits to the right of the decimal point (left if digits is negative). Digits are 0 if not given. Midpoint values are handled using the _Rounding Away From Zero_ convention, which rounds them to the next number away from zero (for example, ROUND(1.85) returns 1.9). | ## [](#related-content)Related Content ###### [](#) How to . . . * [Prerequisites](gs-prereqs.md) * [Install](gs-install.md) * [Build and Run](gs-build.md) . ###### [](#-2) Learn more . . . * [Databases](database.md) * [Documents](document.md) * [Blobs](blob.md) * [Remote Sync Gateway](replication.md) * [Handling Data Conflicts](conflict.md) . ###### [](#-3) Dive Deeper . . . [Mobile Forum](https://forums.couchbase.com/c/mobile/14) | [Blog](https://blog.couchbase.com/) | [Tutorials](https://docs.couchbase.com/tutorials/) .