71 lines
3.7 KiB
Markdown
71 lines
3.7 KiB
Markdown
---
|
|
layout: default
|
|
title: Metadata Queries
|
|
parent: SQL
|
|
nav_order: 9
|
|
---
|
|
|
|
# Metadata queries
|
|
|
|
To see basic metadata about your indices, use the `SHOW` and `DESCRIBE` commands.
|
|
|
|
### Syntax
|
|
|
|
Rule `showStatement`:
|
|
|
|
![showStatement](../../images/showStatement.png)
|
|
|
|
Rule `showFilter`:
|
|
|
|
![showFilter](../../images/showFilter.png)
|
|
|
|
### Example 1: See metadata for indices
|
|
|
|
To see metadata for indices that match a specific pattern, use the `SHOW` command.
|
|
Use the wildcard `%` to match all indices:
|
|
|
|
```sql
|
|
SHOW TABLES LIKE %
|
|
```
|
|
|
|
| TABLE_CAT | TABLE_SCHEM | TABLE_NAME | TABLE_TYPE | REMARKS | TYPE_CAT | TYPE_SCHEM | TYPE_NAME | SELF_REFERENCING_COL_NAME | REF_GENERATION
|
|
:--- | :---
|
|
docker-cluster | null | accounts | BASE TABLE | null | null | null | null | null | null
|
|
docker-cluster | null | employees_nested | BASE TABLE | null | null | null | null | null | null
|
|
|
|
|
|
### Example 2: See metadata for a specific index
|
|
|
|
To see metadata for an index name with a prefix of `acc`:
|
|
|
|
```sql
|
|
SHOW TABLES LIKE acc%
|
|
```
|
|
|
|
| TABLE_CAT | TABLE_SCHEM | TABLE_NAME | TABLE_TYPE | REMARKS | TYPE_CAT | TYPE_SCHEM | TYPE_NAME | SELF_REFERENCING_COL_NAME | REF_GENERATION
|
|
:--- | :---
|
|
docker-cluster | null | accounts | BASE TABLE | null | null | null | null | null | null
|
|
|
|
|
|
### Example 3: See metadata for fields
|
|
|
|
To see metadata for field names that match a specific pattern, use the `DESCRIBE` command:
|
|
|
|
```sql
|
|
DESCRIBE TABLES LIKE accounts
|
|
```
|
|
|
|
| TABLE_CAT | TABLE_SCHEM | TABLE_NAME | COLUMN_NAME | DATA_TYPE | TYPE_NAME | COLUMN_SIZE | BUFFER_LENGTH | DECIMAL_DIGITS | NUM_PREC_RADIX | NULLABLE | REMARKS | COLUMN_DEF | SQL_DATA_TYPE | SQL_DATETIME_SUB | CHAR_OCTET_LENGTH | ORDINAL_POSITION | IS_NULLABLE | SCOPE_CATALOG | SCOPE_SCHEMA | SCOPE_TABLE | SOURCE_DATA_TYPE | IS_AUTOINCREMENT | IS_GENERATEDCOLUMN
|
|
:--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :---
|
|
docker-cluster | null | accounts | account_number | null | long | null | null | null | 10 | 2 | null | null | null | null | null | 1 | | null | null | null | null | NO |
|
|
docker-cluster | null | accounts | firstname | null | text | null | null | null | 10 | 2 | null | null | null | null | null | 2 | | null | null | null | null | NO |
|
|
docker-cluster | null | accounts | address | null | text | null | null | null | 10 | 2 | null | null | null | null | null | 3 | | null | null | null | null | NO |
|
|
docker-cluster | null | accounts | balance | null | long | null | null | null | 10 | 2 | null | null | null | null | null | 4 | | null | null | null | null | NO |
|
|
docker-cluster | null | accounts | gender | null | text | null | null | null | 10 | 2 | null | null | null | null | null | 5 | | null | null | null | null | NO |
|
|
docker-cluster | null | accounts | city | null | text | null | null | null | 10 | 2 | null | null | null | null | null | 6 | | null | null | null | null | NO |
|
|
docker-cluster | null | accounts | employer | null | text | null | null | null | 10 | 2 | null | null | null | null | null | 7 | | null | null | null | null | NO |
|
|
docker-cluster | null | accounts | state | null | text | null | null | null | 10 | 2 | null | null | null | null | null | 8 | | null | null | null | null | NO |
|
|
docker-cluster | null | accounts | age | null | long | null | null | null | 10 | 2 | null | null | null | null | null | 9 | | null | null | null | null | NO |
|
|
docker-cluster | null | accounts | email | null | text | null | null | null | 10 | 2 | null | null | null | null | null | 10 | | null | null | null | null | NO |
|
|
docker-cluster | null | accounts | lastname | null | text | null | null | null | 10 | 2 | null | null | null | null | null | 11 | | null | null | null | null | NO |
|