尝试检查bash脚本中是否存在Mysql用户

我试图检查是否存在MYSQL用户。这是我所能做到的。我无法从输出中获取答案

 #!/bin/bash
echo -e "What is the MYSQL username called"
    read DBUSER
    if [ -z "$DBUSER" ]
    then
    exit

    mysql -uUSER -pPASS -e "SELECT EXISTS(SELECT 1 FROM mysql.user WHERE user = '$DBUSER')";

    if 
    yes
    do this
    else
    do this

这是我得到的输出

+-----------------------------------------------------+
| EXISTS(SELECT 1 FROM mysql.user WHERE user = 'bob') |
+-----------------------------------------------------+
|                                                   1 |
+-----------------------------------------------------+

---

请任何人帮忙

将结果分配给变量可以这样做：

RESULT_VARIABLE="$(mysql -uUSER -pPASS -se "SELECT EXISTS(SELECT 1 FROM mysql.user WHERE user = '$DBUSER')")"

顺便说一句，您还可以在MySQL中为一列添加别名

SELECT EXISTS(SELECT 1 FROM mysql.user WHERE user = '$DBUSER') AS does_it_exist

---

非常感谢你的帮助。这是工作的最终结果

它需要-sse

RESULT_VARIABLE="$(mysql -uUSER -pPASS -sse "SELECT EXISTS(SELECT 1 FROM mysql.user WHERE user = '$DBUSER')")"

if [ "$RESULT_VARIABLE" = 1 ]; then
echo "TRUE"
else
  echo "FALSE"
fi

---

非常感谢。然后我试着去了解结果。如果[$RESULT_VARIABLE=1]，这会给我一个错误；然后回显为真，否则回显重试，这很明显，但只是为了表示肯定。。。这对我使用shell\u exec->$is\u mysql\u user=shell\u exec'mysql-defaults extra file=MYPATHTOSTOREDCREDENTIALS-sse SELECT EXISTSSELECT 1 FROM mysql.user WHERE user=\$用户名。“\”；