ddl

How to change a table ID from serial to identity?

由 随声附和 提交于 2020-12-13 03:06:50
问题 I have the following table in Postgres 10.10: Table "public.client" Column | Type | Collation | Nullable | Default ---------------------+---------+-----------+----------+------------------------------------------ clientid | integer | | not null | nextval('client_clientid_seq'::regclass) account_name | text | | not null | last_name | text | | | first_name | text | | | address | text | | not null | suburbid | integer | | | cityid | integer | | | post_code | integer | | not null | business_phone

ORA-00907: Missing Right Parenthesis On Creating Foreign Key Oracle 12c

由 筅森魡賤 提交于 2020-11-29 09:28:25
问题 I Want To Make a Table Which Include One Auto Generated Primary Key And Two Foreign Keys But I'm Facing This Error... create table answers ( id number generated by default on null as identity primary key , question_id number foreign key references questions(id) , user_id number foreign key references users(id) , answer varchar(1000) , post_date date); create table answers (id number generated by default on null as identity primary key, question_id number foreign key references questions(id),

How can i change existing column as Identity in PostgreSQL 11.1

由 [亡魂溺海] 提交于 2020-07-09 09:53:08
问题 I would like to changes my existing column as Auto Identity in a Postgres Database. I tried with below script but it won't worked. Let me know if you have solution for the same I don't want to use postgres SEQUENCE. I would like to use GENERATED ALWAYS AS IDENTITY . ALTER TABLE public.patient ALTER COLUMN patientid Type int4 USING patientid::int4 GENERATED ALWAYS AS IDENTITY; 回答1: Following the documentation ALTER TABLE patient ALTER patientid SET NOT NULL, ALTER patientid ADD GENERATED

GRANT and REVOKE is DCL or DDL? [closed]

由 て烟熏妆下的殇ゞ 提交于 2020-05-17 05:56:08
问题 Closed. This question is not reproducible or was caused by typos. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 5 days ago . Thanks in advance for everyone, because you are always providing your great knowledge and help me. Currently, I tested myself via dumps and there are many questions where I see that GRANT and REVOKE is a DDL statement. But as I know from internet resources, online courses and etc.

DDL statements in PL/SQL?

由 元气小坏坏 提交于 2020-04-28 15:19:48
问题 I am trying the code below to create a table in PL/SQL: DECLARE V_NAME VARCHAR2(20); BEGIN EXECUTE IMMEDIATE 'CREATE TABLE TEMP(NAME VARCHAR(20))'; EXECUTE IMMEDIATE 'INSERT INTO TEMP VALUES(''XYZ'')'; SELECT NAME INTO V_NAME FROM TEMP; END; / The SELECT statement fails with this error: PL/SQL: ORA-00942: table or view does not exist Is it possible to CREATE, INSERT and SELECT all in a single PL/SQL Block one after other? 回答1: I assume you're doing something like the following: declare v_temp

DDL statements in PL/SQL?

由 为君一笑 提交于 2020-04-28 15:17:32
问题 I am trying the code below to create a table in PL/SQL: DECLARE V_NAME VARCHAR2(20); BEGIN EXECUTE IMMEDIATE 'CREATE TABLE TEMP(NAME VARCHAR(20))'; EXECUTE IMMEDIATE 'INSERT INTO TEMP VALUES(''XYZ'')'; SELECT NAME INTO V_NAME FROM TEMP; END; / The SELECT statement fails with this error: PL/SQL: ORA-00942: table or view does not exist Is it possible to CREATE, INSERT and SELECT all in a single PL/SQL Block one after other? 回答1: I assume you're doing something like the following: declare v_temp

MySQL DDL详情揭露

由 别说谁变了你拦得住时间么 提交于 2020-04-03 19:38:49
前言： MySQL中DDL语句，即数据定义语言，用于创建、删除、修改、库或表结构，对数据库或表的结构操作。常见的有create，alter，drop等。这类语句通常会耗费很大代价，特别是对于大表做表结构变更。本篇文章会揭露各类DDL语句执行的详细情况。 1.Online DDL简介 在MySQL的早期版本中，DDL操作因为锁表会和DML操作发生锁冲突，大大降低并发性。在早期版本中，大部分DDL操作的执行原理就是通过重建表的方式，因为要复制原表数据，所以会长时间锁表，只能读不能写，DDL操作和DML操作有很严重的冲突。从MySQL5.6开始，很多DDL操作过程都进行了改进，出现了Online DDL，用于支持DDL执行期间DML语句的并行操作，提高数据库的吞吐量。 MySQL 在线DDL分为 INPLACE 和 COPY 两种方式，通过在ALTER语句的ALGORITHM参数指定。 ALGORITHM=INPLACE ，可以避免重建表带来的IO和CPU消耗，保证ddl期间依然有良好的性能和并发。 ALGORITHM=COPY ，需要拷贝原始表，所以不允许并发DML写操作，可读。这种copy方式的效率还是不如 inplace ，因为前者需要记录undo和redo log，而且因为临时占用buffer pool引起短时间内性能受影响。 上面只是 Online DDL 内部的实现方式

Flink SQL DDL

由 二次信任 提交于 2020-03-25 09:11:26
Flink 1.10版本支持SQL DDL的特性，本文章以从kafka消费数据，写入jdbc为例介绍整个流程。具体操作如下： 1.下载flink1.10的安装包并解压： https://www.apache.org/dist/flink/flink-1.10.0/flink-1.10.0-bin-scala_2.11.tgz 进入flink的lib目录，采用wget或是本地下载拷贝的方式下载依赖的connector ，需要的依赖有 flink-json-1.10.0.jar，flink-sql-connector-kafka_2.11-1.10.0.jar， flink-jdbc_2.11-1.10.0.jar， mysql-connector-java-5.1.48.jar 2.执行./bin/start-cluster.sh启动flink集群，启动成功后可以在 http://localhost:8081 访问到 Flink Web UI。 3.执行./bin/sql-client.sh embedded 启动 SQL CLI。便会看到松鼠欢迎的界面， 4.使用DDL建立数据源表 CREATE TABLE source_table ( id BIGINT, name STRING, score BIGINT ) WITH ( 'connector.type' = 'kafka',
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