2.5 KiB
slug | sidebar_position | sidebar_label |
---|---|---|
/en/engines/database-engines/sqlite | 55 | SQLite |
SQLite
Allows to connect to SQLite database and perform INSERT
and SELECT
queries to exchange data between ClickHouse and SQLite.
Creating a Database
CREATE DATABASE sqlite_database
ENGINE = SQLite('db_path')
Engine Parameters
db_path
— Path to a file with SQLite database.
Data Types Support
SQLite | ClickHouse |
---|---|
INTEGER | Int32 |
REAL | Float32 |
TEXT | String |
BLOB | String |
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
Database in ClickHouse, connected to the SQLite:
CREATE DATABASE sqlite_db ENGINE = SQLite('sqlite.db');
SHOW TABLES FROM sqlite_db;
┌──name───┐
│ table1 │
│ table2 │
└─────────┘
Shows the tables:
SELECT * FROM sqlite_db.table1;
┌─col1──┬─col2─┐
│ line1 │ 1 │
│ line2 │ 2 │
│ line3 │ 3 │
└───────┴──────┘
Inserting data into SQLite table from ClickHouse table:
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;
┌─col1──┬─col2─┐
│ line1 │ 1 │
│ line2 │ 2 │
│ line3 │ 3 │
│ text │ 10 │
└───────┴──────┘