CODEWITHSUNDEEP
javamysqldatabase
nizarnizario
nizarnizario

Reputation: 11

How I can get all data from a table in Mysql DB with Java

How can I get all data in Mysql DB with JAVA

I Have this code but he get only first row

if (connection != null) {
System.out.println("You made it, take control your database now!");
        Statement st = connection.createStatement();
        String sql = ("SELECT * FROM nc;");
        ResultSet rs = st.executeQuery(sql);

        if(rs.next()) {
        int id = rs.getInt("id");
        String str1 = rs.getString("Name");
        String str2 = rs.getString("City");
System.out.format("%s, %s, %s\n", id, str1, str2);

and i get in the screen : id 0 , Name Nizar, City Casablanca

so how ican get all rows in my database and thank you

Upvotes: 1

Views: 4604

Answers (4)

BobMcGee
BobMcGee

Reputation: 20110

You want to change your if (rs.next()) { To be a while(rs.next()) {

You're only iterating through one row as it is, that will iterate through all of them.

As a best practice, don't make the contents of the while(...) loop too fancy. You want to minimize the per-row processing while iterating, so the connection doesn't stay open too long. Many people just read rows into a List, or print them out (like you're doing).

Upvotes: 0

m0skit0
m0skit0

Reputation: 25873

Replace if(rs.next()) by while(rs.next()).

if(rs.next()) means "if we have one result, move to it and do the following"

while(rs.next()) means "while we still have results, move to the next one and do the following".

Upvotes: 0

MadProgrammer
MadProgrammer

Reputation: 347214

Change your if to a while...

while(rs.next()) {
    int id = rs.getInt("id");
    String str1 = rs.getString("Name");
    String str2 = rs.getString("City");
    System.out.format("%s, %s, %s\n", id, str1, str2);      
}

Upvotes: 0

PSR
PSR

Reputation: 40318

If you use if the block will execute only once.If you use while the block will execute until the condition false

use while instead of if

while(rs.next()) {
        int id = rs.getInt("id");
        String str1 = rs.getString("Name");
        String str2 = rs.getString("City");
System.out.format("%s, %s, %s\n", id, str1, str2);  
}


rs.next()

will return false when all the records are completed

Upvotes: 2

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