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While the internal structure of the docs is already split into many (over 1000) sub-pages, the final display for the `Functions and Operators` page is a single giant page, making navigation harder. This PR splits it into separate pages, one for each group of similar functions and one for the operators. Twelve new pages. This PR also bundles a few other related changes. In total what is done is: * Split functions/operators into 12 pages, one for each group, maintaining the existing split of each function/operator into a snippet with dynamically generated examples * Split esql-commands.md into source-commands.md and processing-commands.md, each of which is split into individual snippets, one for each command * Each command snippet has it's examples split out into separate files, if they were examples that were dynamically generated in the older asciidoc system * The examples files are overwritten by the ES|QL unit tests, using a similar mechanism to the examples written for functions and operators) * Some additional refinements to the Kibana definition and markdown files (nicer operator headings, and display text)
61 lines
2.7 KiB
Markdown
61 lines
2.7 KiB
Markdown
---
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navigation_title: "Implicit casting"
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mapped_pages:
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- https://www.elastic.co/guide/en/elasticsearch/reference/current/esql-implicit-casting.html
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---
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# {{esql}} implicit casting [esql-implicit-casting]
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Often users will input `date`, `date_period`, `time_duration`, `ip` or `version` as simple strings in their queries for use in predicates, functions, or expressions. {{esql}} provides [type conversion functions](/reference/query-languages/esql/functions-operators/type-conversion-functions.md) to explicitly convert these strings into the desired data types.
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Without implicit casting users must explicitly code these `to_X` functions in their queries, when string literals don’t match the target data types they are assigned or compared to. Here is an example of using `to_datetime` to explicitly perform a data type conversion.
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```esql
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FROM employees
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| EVAL dd_ns1=date_diff("day", to_datetime("2023-12-02T11:00:00.00Z"), birth_date)
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| SORT emp_no
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| KEEP dd_ns1
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| LIMIT 1
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```
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## Implicit casting example [esql-implicit-casting-example]
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Implicit casting automatically converts string literals to the target data type. This allows users to specify string values for types like `date`, `date_period`, `time_duration`, `ip` and `version` in their queries.
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The first query can be coded without calling the `to_datetime` function, as follows:
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```esql
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FROM employees
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| EVAL dd_ns1=date_diff("day", "2023-12-02T11:00:00.00Z", birth_date)
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| SORT emp_no
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| KEEP dd_ns1
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| LIMIT 1
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```
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## Operations that support implicit casting [esql-implicit-casting-supported-operations]
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The following table details which {{esql}} operations support implicit casting for different data types.
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| | ScalarFunctions | Operators | [GroupingFunctions](/reference/query-languages/esql/functions-operators/grouping-functions.md) | [AggregateFunctions](/reference/query-languages/esql/functions-operators/aggregation-functions.md) |
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| --- | --- | --- | --- | --- |
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| DATE | Y | Y | Y | N |
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| DATE_PERIOD/TIME_DURATION | Y | N | Y | N |
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| IP | Y | Y | Y | N |
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| VERSION | Y | Y | Y | N |
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| BOOLEAN | Y | Y | Y | N |
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ScalarFunctions includes:
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* [Conditional Functions and Expressions](/reference/query-languages/esql/functions-operators/conditional-functions-and-expressions.md)
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* [Date and Time Functions](/reference/query-languages/esql/functions-operators/date-time-functions.md)
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* [IP Functions](/reference/query-languages/esql/functions-operators/ip-functions.md)
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Operators includes:
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* [Binary Operators](/reference/query-languages/esql/functions-operators/operators.md#esql-binary-operators)
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* [Unary Operator](/reference/query-languages/esql/functions-operators/operators.md#esql-unary-operators)
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* [IN](/reference/query-languages/esql/functions-operators/operators.md#esql-in-operator)
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