INSERT¶
通过在表中插入一行或多行来更新表。插入到表中每个列中的值可以是显式指定的,也可以是查询的结果。
- 另请参阅:
语法¶
INSERT [ OVERWRITE ] INTO <target_table> [ ( <target_col_name> [ , ... ] ) ]
{
VALUES ( { <value> | DEFAULT | NULL } [ , ... ] ) [ , ( ... ) ] |
<query>
}
必填参数¶
target_table
指定要在其中插入行的目标表。
VALUES ( value | DEFAULT | NULL [ , ... ] ) [ , ( ... ) ]
指定要插入到目标表的相应列中的一个或多个值。
在
VALUES
子句中,可以指定以下值:value
:插入显式指定的值。该值可以是字面量或表达式。DEFAULT
:插入目标表中相应列的默认值。NULL
:插入NULL
值。
该子句中的每个值都必须用逗号分隔。
query
指定一个 查询 语句,该语句返回要插入到相应列中的值。这允许您将行从一个或多个源表插入到目标表中。
可选参数¶
OVERWRITE
指定在将值插入到表中之前应截断目标表。请注意,指定此选项不会影响对表的访问控制权限。
带
OVERWRITE
的 INSERT 语句可以在当前事务的作用域内进行处理,从而避免提交事务的 DDL 语句,例如:DROP TABLE t; CREATE TABLE t AS SELECT * FROM ... ;
默认值:无值(在执行插入之前 不会 截断目标表)。
( target_col_name [ , ... ] )
指定目标表中的一列或多列,在其中插入对应的值。指定的目标列数必须与
VALUES
子句中指定的值数或列数(如果这些值是查询的结果)匹配。默认值:无值(目标表中的 所有 列都会更新)。
使用说明¶
使用单个 INSERT 命令,您可以通过在
VALUES
子句中指定以逗号分隔的其他值集,将多行插入到表中。例如,以下子句将在包含 3 列的表中插入 3 行,前两行中插入值
1
、2
和3
,第三行中插入值2
、3
和4
:VALUES ( 1, 2, 3 ) , ( 1, 2, 3 ) , ( 2, 3, 4 )
要使用 INSERT 上的 OVERWRITE 选项,您必须使用对表具有 DELETE 权限的角色,因为 OVERWRITE 将删除表中的现有记录。
某些表达式不能在 VALUES 子句中指定。作为替代方法,可以在查询子句中指定表达式。例如,您可以将以下内容:
INSERT INTO table1 (ID, varchar1, variant1) VALUES (4, 'Fourier', PARSE_JSON('{ "key1": "value1", "key2": "value2" }'));
替换为:
INSERT INTO table1 (ID, varchar1, variant1) SELECT 4, 'Fourier', PARSE_JSON('{ "key1": "value1", "key2": "value2" }');
VALUES 子句限制为 16,384 行。此限制适用于单个 INSERT INTO ...VALUES 语句和单个 INSERT INTO ...SELECT ...FROM VALUES 语句。考虑使用 COPY INTO <table> 命令执行批量数据加载。有关在 SELECT 语句中使用 VALUES 子句的更多信息,请参阅 VALUES。
有关在混合表中插入数据的信息,请参阅 加载数据。
示例¶
以下示例使用 INSERT 命令。
使用查询进行单行插入¶
将三个字符串值转换为日期或时间戳,并将它们插入到 mytable
表中的单行中:
CREATE OR REPLACE TABLE mytable (
col1 DATE,
col2 TIMESTAMP_NTZ,
col3 TIMESTAMP_NTZ);
DESC TABLE mytable;
+------+------------------+--------+-------+---------+-------------+------------+-------+------------+---------+-------------+----------------+
| name | type | kind | null? | default | primary key | unique key | check | expression | comment | policy name | privacy domain |
|------+------------------+--------+-------+---------+-------------+------------+-------+------------+---------+-------------+----------------|
| COL1 | DATE | COLUMN | Y | NULL | N | N | NULL | NULL | NULL | NULL | NULL |
| COL2 | TIMESTAMP_NTZ(9) | COLUMN | Y | NULL | N | N | NULL | NULL | NULL | NULL | NULL |
| COL3 | TIMESTAMP_NTZ(9) | COLUMN | Y | NULL | N | N | NULL | NULL | NULL | NULL | NULL |
+------+------------------+--------+-------+---------+-------------+------------+-------+------------+---------+-------------+----------------+
INSERT INTO mytable
SELECT
TO_DATE('2013-05-08T23:39:20.123'),
TO_TIMESTAMP('2013-05-08T23:39:20.123'),
TO_TIMESTAMP('2013-05-08T23:39:20.123');
SELECT * FROM mytable;
+------------+-------------------------+-------------------------+
| COL1 | COL2 | COL3 |
|------------+-------------------------+-------------------------|
| 2013-05-08 | 2013-05-08 23:39:20.123 | 2013-05-08 23:39:20.123 |
+------------+-------------------------+-------------------------+
与前面的示例类似,但指定仅更新表中的第一列和第三列:
INSERT INTO mytable (col1, col3)
SELECT
TO_DATE('2013-05-08T23:39:20.123'),
TO_TIMESTAMP('2013-05-08T23:39:20.123');
SELECT * FROM mytable;
+------------+-------------------------+-------------------------+
| COL1 | COL2 | COL3 |
|------------+-------------------------+-------------------------|
| 2013-05-08 | 2013-05-08 23:39:20.123 | 2013-05-08 23:39:20.123 |
| 2013-05-08 | NULL | 2013-05-08 23:39:20.123 |
+------------+-------------------------+-------------------------+
使用显式指定的值进行多行插入¶
创建 employees
表,然后通过在 VALUES 子句中以逗号分隔的列表中提供值组,将四行数据插入到该表中:
CREATE TABLE employees (
first_name VARCHAR,
last_name VARCHAR,
workphone VARCHAR,
city VARCHAR,
postal_code VARCHAR);
INSERT INTO employees
VALUES
('May', 'Franklin', '1-650-249-5198', 'San Francisco', 94115),
('Gillian', 'Patterson', '1-650-859-3954', 'San Francisco', 94115),
('Lysandra', 'Reeves', '1-212-759-3751', 'New York', 10018),
('Michael', 'Arnett', '1-650-230-8467', 'San Francisco', 94116);
SELECT * FROM employees;
+------------+-----------+----------------+---------------+-------------+
| FIRST_NAME | LAST_NAME | WORKPHONE | CITY | POSTAL_CODE |
|------------+-----------+----------------+---------------+-------------|
| May | Franklin | 1-650-249-5198 | San Francisco | 94115 |
| Gillian | Patterson | 1-650-859-3954 | San Francisco | 94115 |
| Lysandra | Reeves | 1-212-759-3751 | New York | 10018 |
| Michael | Arnett | 1-650-230-8467 | San Francisco | 94116 |
+------------+-----------+----------------+---------------+-------------+
在多行插入中,请确保插入值的数据类型在各行之间保持一致,因为第一行的数据类型将用作指南。创建表并插入两行:
CREATE OR REPLACE TABLE demo_insert_type_mismatch (v VARCHAR);
第一次插入按预期工作:
INSERT INTO demo_insert_type_mismatch (v) VALUES
('three'),
('four');
+-------------------------+
| number of rows inserted |
|-------------------------|
| 2 |
+-------------------------+
第二次插入失败,因为第二行 ('d'
) 中值的数据类型是字符串,不同于第一行 (3
) 中值的数字数据类型。即使可以将两组值 强制转换 为VARCHAR(这是表中列的数据类型),插入也会失败。即使值 'd'
的数据类型与列 v
的数据类型相同,插入也会失败:
INSERT INTO demo_insert_type_mismatch (v) VALUES
(3),
('d');
100038 (22018): DML operation to table DEMO_INSERT_TYPE_MISMATCH failed on column V with error: Numeric value 'd' is not recognized
当各行的数据类型一致时,插入成功,并且两个数值都被强制转换为 VARCHAR 数据类型:
INSERT INTO demo_insert_type_mismatch (v) VALUES
(3),
(4);
+-------------------------+
| number of rows inserted |
|-------------------------|
| 2 |
+-------------------------+
使用查询进行多行插入¶
将 contractors
表中的多行数据插入到 employees
表中:
仅选择
worknum
列中包含区号650
的行。在
city
列中插入 NULL 值。
SELECT * FROM employees;
+------------+-----------+----------------+---------------+-------------+
| FIRST_NAME | LAST_NAME | WORKPHONE | CITY | POSTAL_CODE |
|------------+-----------+----------------+---------------+-------------|
| May | Franklin | 1-650-249-5198 | San Francisco | 94115 |
| Gillian | Patterson | 1-650-859-3954 | San Francisco | 94115 |
| Lysandra | Reeves | 1-212-759-3751 | New York | 10018 |
| Michael | Arnett | 1-650-230-8467 | San Francisco | 94116 |
+------------+-----------+----------------+---------------+-------------+
CREATE TABLE contractors (
contractor_first VARCHAR,
contractor_last VARCHAR,
worknum VARCHAR,
city VARCHAR,
zip_code VARCHAR);
INSERT INTO contractors
VALUES
('Bradley', 'Greenbloom', '1-650-445-0676', 'San Francisco', 94110),
('Cole', 'Simpson', '1-212-285-8904', 'New York', 10001),
('Laurel', 'Slater', '1-650-633-4495', 'San Francisco', 94115);
SELECT * FROM contractors;
+------------------+-----------------+----------------+---------------+----------+
| CONTRACTOR_FIRST | CONTRACTOR_LAST | WORKNUM | CITY | ZIP_CODE |
|------------------+-----------------+----------------+---------------+----------|
| Bradley | Greenbloom | 1-650-445-0676 | San Francisco | 94110 |
| Cole | Simpson | 1-212-285-8904 | New York | 10001 |
| Laurel | Slater | 1-650-633-4495 | San Francisco | 94115 |
+------------------+-----------------+----------------+---------------+----------+
INSERT INTO employees(first_name, last_name, workphone, city, postal_code)
SELECT contractor_first, contractor_last, worknum, NULL, zip_code
FROM contractors
WHERE CONTAINS(worknum,'650');
SELECT * FROM employees;
+------------+------------+----------------+---------------+-------------+
| FIRST_NAME | LAST_NAME | WORKPHONE | CITY | POSTAL_CODE |
|------------+------------+----------------+---------------+-------------|
| May | Franklin | 1-650-249-5198 | San Francisco | 94115 |
| Gillian | Patterson | 1-650-859-3954 | San Francisco | 94115 |
| Lysandra | Reeves | 1-212-759-3751 | New York | 10018 |
| Michael | Arnett | 1-650-230-8467 | San Francisco | 94116 |
| Bradley | Greenbloom | 1-650-445-0676 | NULL | 94110 |
| Laurel | Slater | 1-650-633-4495 | NULL | 94115 |
+------------+------------+----------------+---------------+-------------+
使用公共表表达式将 contractors
表中的多行数据插入到 employees
表中:
INSERT INTO employees (first_name, last_name, workphone, city, postal_code)
WITH cte AS
(SELECT contractor_first AS first_name,
contractor_last AS last_name,
worknum AS workphone,
city,
zip_code AS postal_code
FROM contractors)
SELECT first_name, last_name, workphone, city, postal_code
FROM cte;
使用源表中 id
列的 INNER JOIN 将两个表(emp_addr
、emp_ph
)中的列插入到第三个表 (emp
) 中:
INSERT INTO emp (id, first_name, last_name, city, postal_code, ph)
SELECT a.id, a.first_name, a.last_name, a.city, a.postal_code, b.ph
FROM emp_addr a
INNER JOIN emp_ph b ON a.id = b.id;
JSON 数据的多行插入¶
将两个 JSON 对象插入到表的 VARIANT 列中:
CREATE TABLE prospects (column1 VARIANT);
INSERT INTO prospects
SELECT PARSE_JSON(column1)
FROM VALUES
('{
"_id": "57a37f7d9e2b478c2d8a608b",
"name": {
"first": "Lydia",
"last": "Williamson"
},
"company": "Miralinz",
"email": "lydia.williamson@miralinz.info",
"phone": "+1 (914) 486-2525",
"address": "268 Havens Place, Dunbar, Rhode Island, 02801"
}')
, ('{
"_id": "57a37f7d622a2b1f90698c01",
"name": {
"first": "Denise",
"last": "Holloway"
},
"company": "DIGIGEN",
"email": "denise.holloway@digigen.net",
"phone": "+1 (979) 587-3021",
"address": "441 Dover Street, Ada, New Mexico, 87105"
}');
使用 OVERWRITE 插入¶
此示例使用带有 OVERWRITE 的 INSERT,在将新记录添加到 employees
表后,从 employees
重新构建 sf_employees
表。
下面是两个表的初始数据:
SELECT * FROM employees;
+------------+-----------+----------------+---------------+-------------+
| FIRST_NAME | LAST_NAME | WORKPHONE | CITY | POSTAL_CODE |
|------------+-----------+----------------+---------------+-------------|
| May | Franklin | 1-650-111-1111 | San Francisco | 94115 |
| Gillian | Patterson | 1-650-222-2222 | San Francisco | 94115 |
| Lysandra | Reeves | 1-212-222-2222 | New York | 10018 |
| Michael | Arnett | 1-650-333-3333 | San Francisco | 94116 |
+------------+-----------+----------------+---------------+-------------+
SELECT * FROM sf_employees;
+------------+-----------+----------------+---------------+-------------+
| FIRST_NAME | LAST_NAME | WORKPHONE | CITY | POSTAL_CODE |
|------------+-----------+----------------+---------------+-------------|
| Mary | Smith | 1-650-999-9999 | San Francisco | 94115 |
+------------+-----------+----------------+---------------+-------------+
此语句使用 OVERWRITE 子句将行插入 sf_employees
表中:
INSERT OVERWRITE INTO sf_employees
SELECT * FROM employees
WHERE city = 'San Francisco';
因为 INSERT 使用了 OVERWRITE 子句,所以 sf_employees
中原来的行消失不见了:
SELECT * FROM sf_employees;
+------------+-----------+----------------+---------------+-------------+
| FIRST_NAME | LAST_NAME | WORKPHONE | CITY | POSTAL_CODE |
|------------+-----------+----------------+---------------+-------------|
| May | Franklin | 1-650-111-1111 | San Francisco | 94115 |
| Gillian | Patterson | 1-650-222-2222 | San Francisco | 94115 |
| Michael | Arnett | 1-650-333-3333 | San Francisco | 94116 |
+------------+-----------+----------------+---------------+-------------+