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Grammar in operators.md
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@ -5,8 +5,7 @@ toc_title: Operators
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# Operators {#operators}
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All operators are transformed to their corresponding functions at the query parsing stage in accordance with their precedence and associativity.
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Groups of operators are listed in order of priority (the higher it is in the list, the earlier the operator is connected to its arguments).
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ClickHouse transforms operators to their corresponding functions at the query parsing stage according to their priority, precedence, and associativity.
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## Access Operators {#access-operators}
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@ -78,7 +77,7 @@ Groups of operators are listed in order of priority (the higher it is in the lis
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EXTRACT(part FROM date);
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```
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Extracts a part from a given date. For example, you can retrieve a month from a given date, or a second from a time.
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Extract parts from a given date. For example, you can retrieve a month from a given date, or a second from a time.
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The `part` parameter specifies which part of the date to retrieve. The following values are available:
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@ -151,7 +150,7 @@ Types of intervals:
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- `YEAR`
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!!! warning "Warning"
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Intervals with different types can’t be combined. You can’t use expressions like `INTERVAL 4 DAY 1 HOUR`. Express intervals in units that are smaller or equal the the smallest unit of the interval, for example `INTERVAL 25 HOUR`. You can use consequtive operations like in the example below.
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Intervals with different types can’t be combined. You can’t use expressions like `INTERVAL 4 DAY 1 HOUR`. Specify intervals in units that are smaller or equal to the smallest unit of the interval, for example, `INTERVAL 25 HOUR`. You can use consecutive operations, like in the example below.
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Example:
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@ -214,7 +213,7 @@ The `transform` function does not work with `NULL`.
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`x -> expr` – The `lambda(x, expr) function.`
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The following operators do not have a priority, since they are brackets:
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The following operators do not have a priority since they are brackets:
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## Array Creation Operator {#array-creation-operator}
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@ -229,7 +228,7 @@ The following operators do not have a priority, since they are brackets:
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All binary operators have left associativity. For example, `1 + 2 + 3` is transformed to `plus(plus(1, 2), 3)`.
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Sometimes this doesn’t work the way you expect. For example, `SELECT 4 > 2 > 3` will result in 0.
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For efficiency, the `and` and `or` functions accept any number of arguments. The corresponding chains of `AND` and `OR` operators are transformed to a single call of these functions.
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For efficiency, the `and` and `or` functions accept any number of arguments. The corresponding chains of `AND` and `OR` operators are transformed into a single call of these functions.
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## Checking for `NULL` {#checking-for-null}
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