ClickHouse/docs/en/engines/database-engines/sqlite.md
2022-04-09 07:34:21 -06:00

81 lines
2.5 KiB
Markdown

---
sidebar_position: 55
sidebar_label: SQLite
---
# SQLite {#sqlite}
Allows to connect to [SQLite](https://www.sqlite.org/index.html) database and perform `INSERT` and `SELECT` queries to exchange data between ClickHouse and SQLite.
## Creating a Database {#creating-a-database}
``` sql
CREATE DATABASE sqlite_database
ENGINE = SQLite('db_path')
```
**Engine Parameters**
- `db_path` — Path to a file with SQLite database.
## Data Types Support {#data_types-support}
| SQLite | ClickHouse |
|---------------|---------------------------------------------------------|
| INTEGER | [Int32](../../sql-reference/data-types/int-uint.md) |
| REAL | [Float32](../../sql-reference/data-types/float.md) |
| TEXT | [String](../../sql-reference/data-types/string.md) |
| BLOB | [String](../../sql-reference/data-types/string.md) |
## Specifics and Recommendations {#specifics-and-recommendations}
SQLite stores the entire database (definitions, tables, indices, and the data itself) as a single cross-platform file on a host machine. During writing SQLite locks the entire database file, therefore write operations are performed sequentially. Read operations can be multitasked.
SQLite does not require service management (such as startup scripts) or access control based on `GRANT` and passwords. Access control is handled by means of file-system permissions given to the database file itself.
## Usage Example {#usage-example}
Database in ClickHouse, connected to the SQLite:
``` sql
CREATE DATABASE sqlite_db ENGINE = SQLite('sqlite.db');
SHOW TABLES FROM sqlite_db;
```
``` text
┌──name───┐
│ table1 │
│ table2 │
└─────────┘
```
Shows the tables:
``` sql
SELECT * FROM sqlite_db.table1;
```
``` text
┌─col1──┬─col2─┐
│ line1 │ 1 │
│ line2 │ 2 │
│ line3 │ 3 │
└───────┴──────┘
```
Inserting data into SQLite table from ClickHouse table:
``` sql
CREATE TABLE clickhouse_table(`col1` String,`col2` Int16) ENGINE = MergeTree() ORDER BY col2;
INSERT INTO clickhouse_table VALUES ('text',10);
INSERT INTO sqlite_db.table1 SELECT * FROM clickhouse_table;
SELECT * FROM sqlite_db.table1;
```
``` text
┌─col1──┬─col2─┐
│ line1 │ 1 │
│ line2 │ 2 │
│ line3 │ 3 │
│ text │ 10 │
└───────┴──────┘
```