update settings.md config doc

kyuubi-common/src/main/scala/org/apache/kyuubi/config/KyuubiConf.scala

@@ -593,7 +593,9 @@ object KyuubiConf {
       " <li>NONE: no authentication check.</li>" +
       " <li>KERBEROS: Kerberos/GSSAPI authentication.</li>" +
       " <li>CUSTOM: User-defined authentication.</li>" +
-      " <li>LDAP: Lightweight Directory Access Protocol authentication.</li></ul>" +
+      " <li>JDBC: JDBC query authentication.</li>" +
+      " <li>LDAP: Lightweight Directory Access Protocol authentication.</li>" +
+      "</ul>" +
       " Note that: For KERBEROS, it is SASL/GSSAPI mechanism," +
       " and for NONE, CUSTOM and LDAP, they are all SASL/PLAIN mechanism." +
       " If only NOSASL is specified, the authentication will be NOSASL." +
@@ -647,45 +649,45 @@ object KyuubiConf {
 
   val AUTHENTICATION_JDBC_DRIVER: OptionalConfigEntry[String] =
     buildConf("kyuubi.authentication.jdbc.driver.class")
-      .doc("Driver class name for JDBC Password Authentication Provider.")
+      .doc("Driver class name for JDBC Authentication Provider.")
       .version("1.6.0")
       .stringConf
       .createOptional
 
   val AUTHENTICATION_JDBC_URL: OptionalConfigEntry[String] =
     buildConf("kyuubi.authentication.jdbc.url")
-      .doc("JDBC URL for JDBC Password Authentication Provider.")
+      .doc("JDBC URL for JDBC Authentication Provider.")
       .version("1.6.0")
       .stringConf
       .createOptional
 
   val AUTHENTICATION_JDBC_USERNAME: OptionalConfigEntry[String] =
     buildConf("kyuubi.authentication.jdbc.username")
-      .doc("Database username for JDBC Password Authentication Provider.")
+      .doc("Database username for JDBC Authentication Provider.")
       .version("1.6.0")
       .stringConf
       .createOptional
 
   val AUTHENTICATION_JDBC_PASSWORD: OptionalConfigEntry[String] =
     buildConf("kyuubi.authentication.jdbc.password")
-      .doc("Database password for JDBC Password Authentication Provider.")
+      .doc("Database password for JDBC Authentication Provider.")
       .version("1.6.0")
       .stringConf
       .createOptional
 
   val AUTHENTICATION_JDBC_QUERY: OptionalConfigEntry[String] =
     buildConf("kyuubi.authentication.jdbc.query")
       .doc("Query SQL template with placeholders " +
-        "for JDBC Password Authentication Provider to execute." +
+        "for JDBC Authentication Provider to execute. " +
+        "Authentication passes if at least one row fetched in the result set." +
         "Available placeholders are: <ul>" +
-        "<li>${username}</li>" +
-        "<li>${password}</li></ul>" +
-        "Don't quote the placeholders, query will be processed as prepared statement, " +
-        "while username and password will be passed as parameters." +
-        "For example: SELECT 1 FROM auth_table WHERE user=${username} AND " +
-        "passwd=MD5(CONCAT(salt,${password})); " +
-        "Will be prepared as: SELECT 1 FROM auth_table " +
-        "WHERE user=? AND passwd=MD5(CONCAT(salt,?)); ")
+        "<li>`${username}`</li>" +
+        "<li>`${password}`</li></ul>" +
+        "eg.: query sql `SELECT 1 FROM auth_table WHERE user=${username} AND " +
+        "passwd=MD5(CONCAT(salt,${password}));` " +
+        "will be prepared as: `SELECT 1 FROM auth_table " +
+        "WHERE user=? AND passwd=MD5(CONCAT(salt,?));`" +
+        " with value replacement of `username` and `password` in string type.")
       .version("1.6.0")
       .stringConf
       .createOptional