✅ 最佳回答: \i tmp.sql -- Create some data to test it on CREATE TABLE events (id integer PRIMARY KEY); INSERT INTO events(id) VALUES(221), (222); CREATE TABLE matches ( id text , event_id text , fighter_a_id text , fighter_b_id text ); INSERT INTO matches(id, event_id...
ALTER TABLE distributors ADD COLUMN address varchar(30); ###To drop a column from a table: ALTER TABLE distributors DROP COLUMN address RESTRICT; ###To change the types of two existing columns in one operation: ALTER TABLE distributors ALTER COLUMN address TYPE varchar(80), ALTER COLUMN name ...
changeColumn( 'test_table', 'something', new TableColumn({ name: 'something', type: 'varchar', length: '18', isNullable: true, }) ); } public async down(queryRunner: QueryRunner): Promise<void> { await queryRunner.changeColumn( 'test_table', 'something', new TableColumn({ name: '...
Multiple methods of keeping your data fresh, including Change Data Capture (CDC) and replication using the xmin system column. All available sync modes, providing flexibility in how data is delivered to your destination. Reliable replication at any table size with checkpointing and chunking of data...
alter table [表名] add[新字段名] [数据类型]; --删除字段: alter table [表名] drop column [字段名]; --删除表的外键约束: alter table 表名 drop constraint 外键名; 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.
GetCurrentDate() { var Year=0; var Month=0; var Day=0; var Cur ...
insert or update operation produces aFALSEresult, an error exception is raised and the insert or update doesn't alter the database. A check constraint specified as a column constraint must reference only that column’s value. An expression appearing in a table constraint can referen...
force_text_transfer - force the provider to replicate all columns using a text representation (which is slower, but may be used to change the type of a replicated column on the subscriber), default is false The subscription_name is used as application_name by the replication connection. This...
MERGE mainly works for co-located distributed Citus tables that merge on the distribution column, and it does not support stable/volatile function calls (e.g. inserting into a table with DEFAULT now()). However, the fact that MERGE is parallelized across nodes can make it a powerful data pr...
在示例类Demo.FileDemo中，ProcessFile()方法接受输入文件和输出文件，并调用SetUpInputFile()和SetUpOutputFile()打开文件，一个用于读取，另一个用于写入。然后，它逐行读取输入文件，并调用ProcessLine()对每行的内容执行一个或多个替换，将每行的新内容写入输出文件。