28 lines
1.6 KiB
Markdown
28 lines
1.6 KiB
Markdown
---
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title: Escape Characters
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description: Detailed rules for using escape characters in TDengine
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slug: /tdengine-reference/sql-manual/escape-characters
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---
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## Escape Character Table
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| Character Sequence | **Represents Character** |
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| :----------------: | ------------------------ |
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| `\'` | Single quote `'` |
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| `\"` | Double quote `"` |
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| `\n` | Newline |
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| `\r` | Carriage return |
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| `\t` | Tab |
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| `\\` | Backslash `\` |
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| `\%` | `%` (rules below) |
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| `\_` | `_` (rules below) |
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## Rules for Using Escape Characters
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1. When escape characters are in identifiers (database name, table name, column name, alias)
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1. Regular identifiers: Directly returns an error for invalid identifiers, as identifiers must consist of numbers, letters, and underscores, and cannot start with a number.
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2. Backtick `` identifiers: Remain unchanged, no escaping applied.
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2. When escape characters are in data
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1. Encountering the defined escape characters will trigger escaping (see below for `%` and `_`); if no matching escape character is found, the escape character `\` will be ignored (and `\x` remains unchanged).
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2. For `%` and `\_`, since these characters are wildcards in `LIKE`, use `\\%` and `\\_` to represent the literal `%` and `\_` in pattern matching with `LIKE`. If `\%` or `\_` is used outside the context of `LIKE` pattern matching, they will be interpreted as the strings `\%` and `\_`, not as `%` and `\_`.
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