# Databases

> **Note:**
> This topic describes displaying and working with databases in the   Database   tool window .
>
>
>
> For information about connection configurations, refer to [Data sources](managing-data-sources.html).

IntelliJ IDEA displays databases that you [select](#show_all_the_schemas_and_databases) to be displayed. It can be useful if you have many databases. Also, by using this approach, you define which databases you want to introspect. During  [introspection](glossary-database-tools-and-sql.html#introspection), IntelliJ IDEA loads the metadata from the database and uses this data later.

Databases ( ![Database](https://resources.jetbrains.com.cn/help/img/idea/2026.2/database-plugin.icons.expui.database.svg)            ) can be found in the   Database   tool window   .

* For the reference on other node and object icons, refer to the [Data sources and their elements](database-tool-window.html#icons-for-data-sources-and-their-elements) chapter of [Database tool window](database-tool-window.html) topic.

* Hide, sort, filter, and group tree objects using the tree objects view options in the [View Options](database-tool-window.html#view_options) menu.

![Databases in Database](https://resources.jetbrains.com.cn/help/img/idea/2026.2/database_object_database.png)

Procedure: Create a database

1. In the   Database   tool window ,    expand the data source tree until the nodes of databases    .

2. Right-click the    data source or database      node and select `New | Database` .

3. In the  Create dialog that opens, enter the name of your database in the Name field.

4. In the Preview pane, you can view and change the generated SQL code.

5. Click OK to  add your database    .

![the Create database dialog](https://resources.jetbrains.com.cn/help/img/idea/2026.2/db_create_database.png)

## Display databases

> **Note:**
> When you create a data source, the data source is created with no databases or schemas selected to display. You need to select the ones you plan to work with yourself.

Procedure: Show and hide databases

* In the   Database   tool window ,  right-click a data source and navigate to `Tools | Manage Shown Schemas…`. Select or clear checkboxes of databases that you want to display or hide. Press `Enter` (Windows), `⏎` (macOS), `⏎` (IntelliJ IDEA Classic (macOS)), `⏎` (macOS System Shortcuts), `Enter` (XWin), `Enter` (GNOME), `Enter` (KDE), `Enter` (Emacs), `Enter` (Sublime Text), `⏎` (Sublime Text (macOS)), `Enter` (NetBeans), `Enter` (Visual Studio), `⏎` (Visual Studio (macOS)), `Enter` (Eclipse), `⏎` (Eclipse (macOS)).

* Click the N of M link near the data source name. In the database and schema selection window, select or clear checkboxes of databases that you want to display or hide. Press `Enter` (Windows), `⏎` (macOS), `⏎` (IntelliJ IDEA Classic (macOS)), `⏎` (macOS System Shortcuts), `Enter` (XWin), `Enter` (GNOME), `Enter` (KDE), `Enter` (Emacs), `Enter` (Sublime Text), `⏎` (Sublime Text (macOS)), `Enter` (NetBeans), `Enter` (Visual Studio), `⏎` (Visual Studio (macOS)), `Enter` (Eclipse), `⏎` (Eclipse (macOS)).

![Show and hide schemas and databases](https://resources.jetbrains.com.cn/help/img/idea/2026.2/show_and_hide_dbs_schemas.png)

Procedure: Use pattern-based filter

To display and introspect all the databases with names that match a regular expression pattern, do the following:

1. In the   Database   tool window ,  click the N of M link near the data source name.

2. In the databases and schemas selector, click the add pattern button near All databases.

![Pattern-based schema filter](https://resources.jetbrains.com.cn/help/img/idea/2026.2/db_pattern_based_schemas_filter.png)

3. In the new filtering node, define the regular expression. For the syntax, click regex for databases near the input field.  For more information about the syntax, refer to  [Summary of regular-expression constructs](#summary_of_regular_expression_constructs).

Press `Enter` (Windows), `⏎` (macOS), `⏎` (IntelliJ IDEA Classic (macOS)), `⏎` (macOS System Shortcuts), `Enter` (XWin), `Enter` (GNOME), `Enter` (KDE), `Enter` (Emacs), `Enter` (Sublime Text), `⏎` (Sublime Text (macOS)), `Enter` (NetBeans), `Enter` (Visual Studio), `⏎` (Visual Studio (macOS)), `Enter` (Eclipse), `⏎` (Eclipse (macOS)) to apply the filter in the selector.

![Regular expressions in pattern-based schema filter](https://resources.jetbrains.com.cn/help/img/idea/2026.2/pattern_based_schemas_filter_regexp.png)

4. Press `Enter` (Windows), `⏎` (macOS), `⏎` (IntelliJ IDEA Classic (macOS)), `⏎` (macOS System Shortcuts), `Enter` (XWin), `Enter` (GNOME), `Enter` (KDE), `Enter` (Emacs), `Enter` (Sublime Text), `⏎` (Sublime Text (macOS)), `Enter` (NetBeans), `Enter` (Visual Studio), `⏎` (Visual Studio (macOS)), `Enter` (Eclipse), `⏎` (Eclipse (macOS)) to apply the filter in   Database   tool window .

The filtering node with filter can be added under any node, including another filtering node.

> **Note:**
> Multiple patterns combine multiplicities, not intersect them.

> **Note:**
> The All schemas node behaves differently now: it doesn't select the default schema automatically. You need to select between All schemas, Default schema, or a filtering node.

Procedure: Show all the schemas and databases

* To display all the available databases in the   Database   tool window  ( `View  | Tool Windows |  Database` ), click the Show Options Menu button and select the All Namespaces option.

* Enabled ![Show All Namespaces is enabled](https://resources.jetbrains.com.cn/help/img/idea/2026.2/show_all_namespaces_enabled.png)

* Disabled ![Show All Namespaces is disabled](https://resources.jetbrains.com.cn/help/img/idea/2026.2/show_all_namespaces_disabled.png)

Procedure: Force refresh schema information

The Force Refresh action clears the data source information from cache and loads it again from scratch.

* In the   Database   tool window ,  right-click a data source and select `Diagnostics | Force Refresh`.

Procedure: Generate a diagram for a database

* In the   Database   tool window ,  right-click a database and select `Diagrams | Show Diagram`.

![Generate a diagram for a database object](https://resources.jetbrains.com.cn/help/img/idea/2026.2/create_diagram_for_database.png)

## Summary of regular-expression constructs

For full information, refer to [Full Java Regular Expressions syntax description](https://docs.oracle.com/javase/1.5.0/docs/api/java/util/regex/Pattern.html) and [Using Regular Expressions in Java](https://www.regular-expressions.info/java.html).

| Construct | Matches |
| --- | --- |
| Characters |
| `x` | The character x |
| `\\` | The backslash character |
| `\0n` | The character with octal value 0n (0 <= n <= 7) |
| `\0nn` | The character with octal value 0nn (0 <= n <= 7) |
| `\0mnn` | The character with octal value 0mnn (0 <= m <= 3, 0 <= n <= 7) |
| `\xhh` | The character with hexadecimal value 0xhh |
| `\uhhhh` | The character with hexadecimal value 0xhhhh |
| `\t` | The tab character ('\u0009') |
| `\n` | The newline (line feed) character ('\u000A') |
| `\r` | The carriage-return character ('\u000D') |
| `\f` | The form-feed character ('\u000C') |
| `\a` | The alert (bell) character ('\u0007') |
| `\e` | The escape character ('\u001B') |
| `\cx` | The control character corresponding to x |
| Character classes |
| `[abc]` | a, b, or c (simple class) |
| `[^abc]` | Any character except a, b, or c (negation) |
| `[a-zA-Z]` | a through z or A through Z, inclusive (range) |
| `[a-d[m-p]]` | a through d, or m through p: [a-dm-p] (union) |
| `[a-z&&[def]]` | d, e, or f (intersection) |
| `[a-z&&[^bc]]` | a through z, except for b and c: [ad-z] (subtraction) |
| `[a-z&&[^m-p]]` | a through z, and not m through p: [a-lq-z](subtraction) |
| Predefined character classes |
| `.` | Any character (may or may not match line terminators) |
| `\d` | A digit: [0-9] |
| `\D` | A non-digit: [^0-9] |
| `\s` | A whitespace character: [ \t\n\x0B\f\r] |
| `\S` | A non-whitespace character: [^\s] |
| `\w` | A word character: [a-zA-Z_0-9] |
| `\W` | A non-word character: [^\w] |
| POSIX character classes (US-ASCII only) |
| `\p{Lower}` | A lower-case alphabetic character: [a-z] |
| `\p{Upper}` | An upper-case alphabetic character:[A-Z] |
| `\p{ASCII}` | All ASCII:[\x00-\x7F] |
| `\p{Alpha}` | An alphabetic character:[\p{Lower}\p{Upper}] |
| `\p{Digit}` | A decimal digit: [0-9] |
| `\p{Alnum}` | An alphanumeric character:[\p{Alpha}\p{Digit}] |
| `\p{Punct}` | Punctuation: One of !"#$%&'()*+,-./:;=>?@[\]^_`{\|}~ |
| `\p{Graph}` | A visible character: [\p{Alnum}\p{Punct}] |
| `\p{Print}` | A printable character: [\p{Graph}\x20] |
| `\p{Blank}` | A space or a tab: [ \t] |
| `\p{Cntrl}` | A control character: [\x00-\x1F\x7F] |
| `\p{XDigit}` | A hexadecimal digit: [0-9a-fA-F] |
| `\p{Space}` | A whitespace character: [ \t\n\x0B\f\r] |
| java.lang.Character classes (simple java character type) |
| `\p{javaLowerCase}` | Equivalent to java.lang.Character.isLowerCase() |
| `\p{javaUpperCase}` | Equivalent to java.lang.Character.isUpperCase() |
| `\p{javaWhitespace}` | Equivalent to java.lang.Character.isWhitespace() |
| `\p{javaMirrored}` | Equivalent to java.lang.Character.isMirrored() |
| Classes for Unicode blocks and categories |
| `\p{InGreek}` | A character in the Greek block (simple block) |
| `\p{Lu}` | An uppercase letter (simple category) |
| `\p{Sc}` | A currency symbol |
| `\P{InGreek}` | Any character except one in the Greek block (negation) |
| `[\p{L}&&[^\p{Lu}]]` | Any letter except an uppercase letter (subtraction) |
| Boundary matchers |
| `^` | The beginning of a line |
| `$` | The end of a line |
| `\b` | A word boundary |
| `\B` | A non-word boundary |
| `\A` | The beginning of the input |
| `\G` | The end of the previous match |
| `\Z` | The end of the input but for the final terminator, if any |
| `\z` | The end of the input |
| Greedy quantifiers |
| `X?` | X, once or not at all |
| `X*` | X, zero or more times |
| `X+` | X, one or more times |
| `X{n}` | X, exactly n times |
| `X{n,}` | X, at least n times |
| `X{n,m}` | X, at least n but not more than m times |
| Reluctant quantifiers |
| `X??` | X, once or not at all |
| `X*?` | X, zero or more times |
| `X+?` | X, one or more times |
| `X{n}?` | X, exactly n times |
| `X{n,}?` | X, at least n times |
| `X{n,m}?` | X, at least n but not more than m times |
| Possessive quantifiers |
| `X?+` | X, once or not at all |
| `X*+` | X, zero or more times |
| `X++` | X, one or more times |
| `X{n}+` | X, exactly n times |
| `X{n,}+` | X, at least n times |
| `X{n,m}+` | X, at least n but not more than m times |
| Logical operators |
| `XY` | X followed by Y |
| `X\|Y` | Either X or Y |
| `(X)` | X, as a capturing group |
| Back references |
| `\n` | Whatever the nth capturing group matched |
| Quotation |
| `\` | Nothing, but quotes the following character |
| `\Q` | Nothing, but quotes all characters until \E |
| `\E` | Nothing, but ends quoting started by \Q |
| Special constructs (non-capturing) |
| `(?:X)` | X, as a non-capturing group |
| `(?idmsux-idmsux)` | Nothing, but turns match flags on - off |
| `(?idmsux-idmsux:X)` | X, as a non-capturing group with the given flags on - off |
| `(?=X)` | X, via zero-width positive lookahead |
| `(?!X)` | X, via zero-width negative lookahead |
| `(?<=X)` | X, via zero-width positive lookbehind |
| `(?<!X)` | X, via zero-width negative lookbehind |
| `(?>X)` | X, as an independent, non-capturing group |

### Reference

[Create and Modify dialog](create-and-modify-dialogs.html#schemas)       [Data sources and their elements](database-tool-window.html#icons-for-data-sources-and-their-elements)

### Related

[Introspection](glossary-database-tools-and-sql.html#introspection)

### Tool Windows

[Database tool window](database-tool-window.html)

### Navigation

### Language and Framework-Specific Guidelines

[Database Tools and SQL](relational-databases.html)