INSERT
Writing data.
Databend guarantees data integrity. In Databend, Insert, Update, and Delete operations are guaranteed to be atomic, which means that all data in the operation must succeed or all must fail.
Insert Into Statement
Syntax
INSERT INTO|OVERWRITE [db.]table [(c1, c2, c3)] VALUES (v11, v12, v13), (v21, v22, v23), ...
Local engine is one of Memory, Parquet, JSONEachRow, Null or CSV, data will be stored in the DatabendQuery memory/fs locally.
Remote engine is remote, will be stored in the remote DatabendStore cluster.
Examples
Example:
CREATE TABLE test(a INT UNSIGNED, b Varchar);
INSERT INTO test(a,b) VALUES(888, 'stars');
INSERT INTO test VALUES(1024, 'stars');
SELECT * FROM test;
+------+-------+
| a | b |
+------+-------+
| 888 | stars |
| 1024 | stars |
+------+-------+
INSERT OVERWRITE test VALUES(2048, 'stars');
SELECT * FROM test;
+------+-------+
| a | b |
+------+-------+
| 2048 | stars |
+------+-------+
Inserting the Results of SELECT
Syntax
INSERT INTO [db.]table [(c1, c2, c3)] SELECT ...
Columns are mapped according to their position in the SELECT clause, So the number of columns in SELECT should be greater or equal to the INSERT table.
The data type of columns in the SELECT and INSERT table could be different, if necessary, type casting will be performed.
Examples
Example:
CREATE TABLE select_table(a VARCHAR, b VARCHAR, c VARCHAR);
INSERT INTO select_table VALUES('1','11','abc');
SELECT * FROM select_table;
+------+------+------+
| a | b | c |
+------+------+------+
| 1 | 11 | abc |
+------+------+------+
CREATE TABLE test(c1 TINTINT UNSIGNED, c2 BIGINT UNSIGNED, c3 VARCHAR) ;
INSERT INTO test SELECT * FROM select_table;
SELECT * from test;
+------+------+------+
| c1 | c2 | c3 |
+------+------+------+
| 1 | 11 | abc |
+------+------+------+
Aggregate Example:
-- create table
CREATE TABLE base_table(a INT);
CREATE TABLE aggregate_table(b INT);
-- insert some data to base_table
INSERT INTO base_table VALUES(1),(2),(3),(4),(5),(6);
-- insert into aggregate_table from the aggregation
INSERT INTO aggregate_table SELECT SUM(a) FROM base_table GROUP BY a%3;
SELECT * FROM aggregate_table ORDER BY b;
+------+
| b |
+------+
| 5 |
| 7 |
| 9 |
+------+
Insert with DEFAULT to fill default value
Syntax
INSERT INTO [db.]table [(c1, c2, c3)] VALUES (v1|DEFAULT, v2|DEFAULT, v3|DEFAULT) ...
Examples
CREATE TABLE t_insert_default(a int null, b int default 2, c float, d varchar default 'd');
INSERT INTO t_insert_default VALUES (default, default, default, default), (1, default, 1.0, default), (3, 3, 3.0, default), (4, 4, 4.0, 'a');
SELECT * FROM t_insert_default;
+------+------+------+------+
| a | b | c | d |
+------+------+------+------+
| NULL | 2 | 0.0 | d |
| 1 | 2 | 1.0 | d |
| 3 | 3 | 3.0 | d |
| 4 | 4 | 4.0 | a |
+------+------+------+------+
Insert with Stage Attachment
This method is only available with native http api currently.
Anything after VALUES will be ignored if a stage is attached to the query.
Syntax
INSERT INTO [db.]table [(c1, c2, c3)] VALUES
Examples
CREATE TABLE t_insert_stage(a int null, b int default 2, c float, d varchar default 'd');
1,1.0
2,2.0
3,3.0
4,4.0
Upload values.csv into stages:
curl -H "stage_name:my_int_stage" -F "upload=@./values.csv" -XPUT http://root:@localhost:8000/v1/upload_to_stage
Insert with the uploaded stage:
curl -d '{"sql": "insert into t_insert_stage (a, c) values", "stage_attachment": {"location": "@my_int_stage/values.csv", "file_format_options": {}, "copy_options": {}}}' -H 'Content-type: application/json' http://root:@localhost:8000/v1/query
file_format_options and copy_options are same with the COPY INTO command.
Check if the insert succeeded:
SELECT * FROM t_insert_stage;
+------+------+------+------+
| a | b | c | d |
+------+------+------+------+
| 1 | 2 | 1.0 | d |
| 2 | 2 | 2.0 | d |
| 3 | 2 | 3.0 | d |
| 4 | 2 | 4.0 | d |
+------+------+------+------+