#课程作业

1.gsql命令连到数据库omm

#常用参数
gsql -r
或
gsql -d omm -p 5432 -r

omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=# 

2.查看数据库的版本、版权信息

omm=# select version();
                                                                        version                                                                        
-------------------------------------------------------------------------------------------------------------------------------------------------------
 (openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr   on aarch64-unknown-linux-gnu, compiled by g++ (GCC) 7.3.0, 64-bit
(1 row)

omm=# show server_version;
 server_version 
----------------
 9.2.4
(1 row)

omm=#  \copyright
GaussDB Kernel Database Management System
Copyright (c) Huawei Technologies Co., Ltd. 2018. All rights reserved.

3.常见元命令使用

4.使用两种方法，连到postgres数据库中

gsql -r或gsql -d omm -p 5432 -r

5.测试gsql中的默认事务自动提交功能

–查看gsql中事务是否默认为自动提交 show AUTOCOMMIT;

–测试gsql中事务默认为自动提交功能 create table customer_new as select * from customer_t;

\q

–重新登录后看到之前创建的表customer_new： gsql -d postgres -p 5432 -r

\dt

6.测试gsql中的事务手动提交功能

\set AUTOCOMMIT off

7.了解gsql相关帮助

omm@modb:~$ gsql --help
gsql is the openGauss interactive terminal.

Usage:
gsql [OPTION]… [DBNAME [USERNAME]]

General options:
-c, --command=COMMAND run only single command (SQL or internal) and exit
-d, --dbname=DBNAME database name to connect to (default: “omm”)
-f, --file=FILENAME execute commands from file, then exit
-l, --list list available databases, then exit
-v, --set=, --variable=NAME=VALUE
set gsql variable NAME to VALUE
-V, --version output version information, then exit
-X, --no-gsqlrc do not read startup file (~/.gsqlrc)
-1 (“one”), --single-transaction
execute command file as a single transaction
-?, --help show this help, then exit

-k, --with-key=KEY the key for decrypting the encrypted file
-L, --log-file=FILENAME send session log to file
-m, --maintenance can connect to cluster during 2-pc transaction recovery
-n, --no-libedit disable enhanced command line editing (libedit)
Input and output options:
-a, --echo-all echo all input from script
-e, --echo-queries echo commands sent to server
-E, --echo-hidden display queries that internal commands generate
-S, --single-line single-line mode (end of line terminates SQL command)

Output format options:
-A, --no-align unaligned table output mode
-F, --field-separator=STRING
set field separator (default: “|”)
-H, --html HTML table output mode
-P, --pset=VAR[=ARG] set printing option VAR to ARG (see \pset command)
-R, --record-separator=STRING
set record separator (default: newline)
-r -o, --output=FILENAME send query results to file (or |pipe)
-q, --quiet run quietly (no messages, only query output)
-C, --enable-client-encryption enable client encryption feature
-s, --single-step single-step mode (confirm each query)
if this parameter is set,use libedit
-t, --tuples-only print rows only
-T, --table-attr=TEXT set HTML table tag attributes (e.g., width, border)
-x, --expanded turn on expanded table output
-z, --field-separator-zero
set field separator to zero byte
-0, --record-separator-zero
set record separator to zero byte
-2, --pipeline use pipeline to pass the password, forbidden to use in terminal
must use with -c or -f

Connection options:
-h, --host=HOSTNAME database server host or socket directory (default: “local socket”)
allow multi host IP address with comma separator in centralized cluster
-p, --port=PORT database server port (default: “5432”)
-U, --username=USERNAME database user name (default: “omm”)
-W, --password=PASSWORD the password of specified database user