获取列名称并将其写入文件

Hi guys i wrote a bash script that execute a query e and print the result into a file but it doesn't work

大家好我写了一个bash脚本执行查询e并将结果打印到文件但它不起作用

source ../db.config
msqlcmd="mysql -u $DB_USER -p$DB_PASS -s -B -q"
echo "USE INFORMATION_SCHEMA;\nSELECT * FROM COLUMNS" | $mysqlcmd > ../tmpsql/columns.txt

Into the db.config there are the credential to access to db

进入db.config有访问db的凭据

3 个解决方案

#1

You don't need to reinvent the wheel to get mysql login credentials. Use mysql_config_editor to store your credentials encrypted in ~/.mylogin.cnf, then you can do the whole thing in a simple one-liner e.g.

您不需要重新发明*来获取mysql登录凭据。使用mysql_config_editor存储在〜/ .mylogin.cnf中加密的凭据，然后你可以用一个简单的单行代码来完成整个过程。

mysql -s -B -q -e "select * from information_schema.columns" | tee ./tmpsql/columns.txt

#2

try the following code:

尝试以下代码：

source ../db.config
echo -e "USE INFORMATION_SCHEMA;\nSELECT * FROM COLUMNS" | mysql -u $DB_USER -p$DB_PASS -s -B -q > ../tmpsql/columns.txt

#3

Don't put command in variables as [ this ] answer nicely summarizes.

不要把命令放在变量中，因为[this]回答很好地总结了。

A [ heredoc ] is your friend here.

[heredoc]是你的朋友。

mysql -u "$db_user" -p "$db_pass" -s -B -q <<-EOF > ../tmpsql/columns.txt
USE INFORMATION_SCHEMA;
SELECT * FROM COLUMNS;
EOF

All good :-)

都好：-）

^{Note: Don't use full uppercase identifiers like $DB_USER for user defined variables as it may conflict with built-in shell variables. Double quoting variables is also a standard practice.}

注意：不要对用户定义的变量使用完整的大写标识符，如$ DB_USER，因为它可能与内置的shell变量冲突。双引号变量也是一种标准做法。

#1