Error ora-28547 or ora-03135 when Navicat connects to Oracle Database

Navicat Preminm 12 or 15 Connect Oracle Database time , Report errors ：
ORA-03135: connection lost contact...

reason

Oracle Instant Client The version of is wrong

Download driver

• By the following order , Get installation Oracle Version number of the server

`select * from v$version`

• To determine the Oracle After the version of the database , download Oracle Instant Client client

Download url ：https://www.oracle.com/cn/database/technologies/instant-client/downloads.html

Select the corresponding operating system Oracle Instant Client client , Such as windows

Download the corresponding version of InstantClient-basic and InstantClient-sqlplus, What I have here is Version 12.2.x

• Unzip the files to the folder where the software is installed Instantclient_xx_x Inside , Such as instantclient_12_2

To configure Navicat

open Navicat Customer order tool , choice Tools -> Options menu , Select... In the dialog box that opens Environmental Science label

Set up SQL*Plus The executable of sqlplus.exe And OCI Environmental oci.dll The file is the corresponding file just downloaded and decompressed , As shown in the figure below ：

After configuration , restart Navicat！！！

Connect the test

Input host 、 port 、 service name 、 User name and password information , Click connect test , Test whether the configuration is successful