The import javax.servlet can't be resolved

Error : The import javax.servlet can't be resolved in eclipse

Soultion

You need to add the Servlet API to your classpath. In Tomcat 7.0, this is in a JAR called servlet-api.jar in Tomcat's lib folder.
steps to add the JAR into your project class path.

Right-click the project, click Properties.
Choose Java Build Path.
Click Add External JARs
Browse to find servlet-api.jar and select it.
Click OK to update the build path.
Clean and build the project

Remove Carriage return in varchar column in sql

Issue

I have a mysql table with VARCHAR column which contains String values. Sometimes at the end of the string there is a carriage return (\r). I only want to delete the \r at the end of the string if it exists.

Solution

A carriage return is CHAR(13)

The following code will remove Carriage return 

UPDATE table_name set column_name=REPLACE(column_name,char(13),'')

Remove a character from a string in mysql

Issue 

I have a mysql table with a column name "sequence". sequence column contains protein sequence starting with "protein name > sequence letters"
I need to remove the characters left to ">" including >

for eg: for the input sequence 
Influenza A virus > MKAKLLVLLCAFTATYA
the output should be
MKAKLLVLLCAFTATYA

Solution

You can use SUBSTRING_INDEX(str,delim,count) 

SUBSTRING_INDEX returns the substring from string str before count occurrences of the delimiter delim. If count is positive, everything to the left of the final delimiter (counting from the left) is returned. If count is negative, everything to the right of the final delimiter (counting from the right) is returned. SUBSTRING_INDEX() performs a case-sensitive match when searching for delim.

you can use

update table_name set column_name = SUBSTRING_INDEX(column_name, '>', -1);

Trim all the values in a column in a sql

Trim all the values in a column in a sql

SQL does not have a trim function. You'll need to use RTRIM and LTRIM together.

update MyTable set Name = RTRIM(LTRIM((name))

java.lang.classnotfoundexception com.mysql.jdbc.driver in jsp

Issue


When i try to have simple jdbc connection to mysql  in my jsp file, i get following console output in eclipse:
console output in eclipse:
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver

When i tried to have the same kind of connection from a simple java file it was working.

Solution

You should put the mysql connector JAR file in WEB-INF/lib directory of your project. Clean Build the project and restart the server.

Add Mysql connector in eclipse classpath

Add Mysql connector in eclipse classpath

1. Download mysql connector jar from
http://dev.mysql.com/downloads/connector/j/
2. Open eclipse in java EE perspective (top right corner)
3. Right click the project go to Properties.
4. Choose Java Build Path and then Select Libraries tab
5. Click Add External JARs  and add the path of the mysql connector jar
6. Click Ok button and clean and build the project

Properties window for my java project

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver error

Issue

When I try connect my java program to mysql database using eclipse,i am getting the run time error
 "java.lang.ClassNotFoundException: com.mysql.jdbc.Driver"

Solution

The reason for the error is you don't have mysql-connector.jar in your Classpath. This jar
contains "com.mysql.jdbc.Driver" class and it must be present in java classpath in order to successful connection to mysql database.
you can downlad mysql-connector.jar from
http://dev.mysql.com/downloads/connector/j/

Click here for adding mysql connector jar to eclipseclass path