I'm trying to create a table similar to a ready table I created before (a template, if you will) where the only variable should be the table name.
This is what I've tried so far:
I exported the template table to mysql code and copied the code to a preparedStatement object as such:
createNewLineTableStatement = constantLink.prepareStatement("CREATE TABLE IF NOT EXISTS ? (" +
" `index` int(5) NOT NULL," +
" `station` int(5) NOT NULL," +
" PRIMARY KEY (`index`)," +
" UNIQUE KEY `station` (`station`)" +
") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;\");");
Than I try to execute the code by calling the following function:
private static boolean createNewLineTable(String tableName) throws SQLException{
createNewLineTableStatement.setString(1, tableName);
if (createNewLineTableStatement.executeUpdate() == Statement.EXECUTE_FAILED)
return false;
return true;
}
But I'm getting a syntax error exception:
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''line_37_var_1' ( `index` int(5) NOT NULL, `station` int(5) NOT NULL, PRIMARY' at line 1
How can I fix the code? OR is there a cleaner, better way to do the same thing? Maybe creating a script with a user variable? I thought of that but I've never used .sql script before.
Problem 1: You can't use a prepared statement parameter as the table name.
Problem 2: You have an unmatched paren and extra characters ");at the end of your statement.
Your query string should look something like:
String query = "CREATE TABLE IF NOT EXISTS `" + tableName + "` (" +
" `index` int(5) NOT NULL," +
" `station` int(5) NOT NULL," +
" PRIMARY KEY (`index`)," +
" UNIQUE KEY `station` (`station`)" +
") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci";
by design, TableName and ColumnNames cannot be parameterized.
If you are scared about SQL Injection, create a custom function to check for malicious tableName. It is safe if the value comes inside of your application.
Then concatenate it in the string, add backtick for first level of defense :D
String tableName = "Your tableName";
String query = "CREATE TABLE IF NOT EXISTS `" + tableName + "` (" +
" `index` int(5) NOT NULL," +
" `station` int(5) NOT NULL," +
" PRIMARY KEY (`index`)," +
" UNIQUE KEY `station` (`station`)" +
") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci";
You are missing Table name and i think that "?" shouldn't be there.
I will be something like
"CREATE TABLE IF NOT EXISTS YOURTABLE" + the following code
Related
I am trying To Create Tables in mysql dynamically And Assign them Name Using The Email Address User Provided. But Whenever I try to Assign Table Name dynamically it shows me error and i don,t know anyother way to fulfil my requirement.
Here is The Code I Wrote
String TableName = Email.getText();
try {
String myTableName = "CREATE TABLE '" + TableName + "' "
+ "(id INTEGER not NULL, "
+ " first VARCHAR(255), "
+ " last VARCHAR(255), "
+ " age INTEGER, "
+ " PRIMARY KEY ( id ))";;
Class.forName(m.RegisterationString);
java.sql.Connection con;
con = DriverManager.getConnection(m.URL, m.UserName, m.Password);
Statement State = con.createStatement();
//This line has the issue
State.executeUpdate(myTableName);
System.out.println("Table Created");
}
In MySQL the name of table should not be between '' it can be between :
String myTableName ="CREATE TABLE `" + tableName + "`"
//--------------------------------^-----------------^
Note for good pratice don't start the name of variable with upper letter like State or TableName, Email
I've got a database set up to store notes. I want to auto increment the first column. I've tried this, but when I read from the database every result in that column is 'null'.This is the code for creating the DB.
private static final String NOTES_TABLE_CREATE =
"CREATE TABLE " + NOTES_TABLE_NAME + " (" +
COLUMN_NAMES[0] + " INTEGER AUTO_INCREMENT, " +
COLUMN_NAMES[1] + " TEXT, " +
COLUMN_NAMES[2] + " TEXT, " +
COLUMN_NAMES[3] + " TEXT, " +
COLUMN_NAMES[4] + " TEXT, " +
COLUMN_NAMES[5] + " TEXT, " +
COLUMN_NAMES[6] + " TEXT);";
This is the code for getting the DB result.
SQLiteDatabase db = this.getReadableDatabase();
Cursor result = db.query(NOTES_TABLE_NAME, COLUMN_NAMES, null, null, null, null, null, null);
result.moveToFirst();
result.moveToNext();
System.out.println(result.getInt(0));
System.out.println(result.getString(1));
This is the output from logcat
04-09 17:56:17.981 22147-22147/com.example.a8460p.locationotes I/System.out: 0
04-09 17:56:17.981 22147-22147/com.example.a8460p.locationotes I/System.out: notetitle1234567890
AUTO_INCREMENT (as opposed to INTEGER PRIMARY KEY AUTOINCREMENT) is not supported in sqlite.
This is a little non-obvious, because sqlite silently ignores column constraints it does not recognize:
sqlite> CREATE TABLE test (
a INTEGER FABBELBABBEL NOT NULL
);
sqlite> .schema test
CREATE TABLE test (a INTEGER FABBELBABBEL NOT NULL);
sqlite> INSERT INTO test (a) VALUES (1);
sqlite> INSERT INTO test (a) VALUES (NULL);
Error: NOT NULL constraint failed: test.a
AUTOINCREMENT on the other hand, is supported for integer primary keys and only there, so the obvious workaround attempt is not supported, either:
sqlite> CREATE TABLE test (a INTEGER AUTOINCREMENT NOT NULL, b INTEGER);
Error: near "AUTOINCREMENT": syntax error
In short: Auto increment is only available for integer primary keys.
Here's the SQL I've tried so far to create the table
CREATE TABLE tblPosts (nId INTEGER PRIMARY KEY GENERATED ALWAYS AS IDENTITY,
strContent VARCHAR(140) NOT NULL,
strLink VARCHAR(200),
strImage VARCHAR(200));
using
String sql = "INSERT INTO tblPosts VALUES ('" + textFieldContent.getText() + "', '" +
textFieldLink.getText() + "', '" + textFieldImage.getText() + "')";
I get an error telling me I'm not providing the nId column value which I'm not but if the column auto-increments I'm not supposed to right?
I've also tried using the IDE to create the table on the database as described here
Alter a table column with auto increment by 1 in derby
Same response though. Any suggestions?
You need to include Start with 1, Increment by 1
Like this
CREATE TABLE tblPosts (nId INTEGER PRIMARY KEY GENERATED ALWAYS AS IDENTITY(Start with 1, Increment by 1),
strContent VARCHAR(140) NOT NULL,
strLink VARCHAR(200)
I would guess that since you're not specifying the column names in the SELECT, it is getting confused as to which columns the data should go in. I would specify the column names in your INSERT command.
You need to set THAT auto_increment column to DEFAULT like this:
String sql = "INSERT INTO tblPosts VALUES ( DEFAULT, '" + textFieldContent.getText() + "', '" +
textFieldLink.getText() + "', '" + textFieldImage.getText() + "')";
I am using oracle 10g and I wrote a create table query like this -
String UserTable="CREATE TABLE UserDetail ( \n" +
" idNo INT(64) NOT NULL , \n" +
" name VARCHAR(50),\n" +
" email VARCHAR(50), \n" +
" state VARCHAR(50),\n"+
" country VARCHAR(50),\n" +
" CONSTRAINT person_pk PRIMARY KEY ('idNo')"
+ ");";
// Connection con2=DriverManager.getConnection(DbAddress,"vivek","123456");
PreparedStatement st2=conn.prepareStatement(UserTable);
st2.executeUpdate();
conn.close();
but it gives following exception-
java.sql.SQLSyntaxErrorException: ORA-00907: missing right parenthesis
on syssout it the query becomes this -
CREATE TABLE UserDetail (
idNo INT(64) NOT NULL ,
name VARCHAR(50),
email VARCHAR(50),
state VARCHAR(50),
country VARCHAR(50),
CONSTRAINT person_pk PRIMARY KEY (idNo)
);
please help.
Remove the below line
CONSTRAINT person_pk PRIMARY KEY ('idNo')
Use the below line in your code instead
CONSTRAINT person_pk PRIMARY KEY (idNo)
oh I got the solution- I was using Int instead of Number and it was not supported. the query should be-
"CREATE TABLE UserDetail ( \n" +
" idNo NUMBER NOT NULL , \n" +
" name VARCHAR(50),\n" +
" email VARCHAR(50), \n" +
" state VARCHAR(50),\n"+
" country VARCHAR(50),\n" +
" CONSTRAINT person_pk PRIMARY KEY ('idNo')"
+ ");";
when i create column family using the cql it gives me very unexpected output.
public static void createColumnfamily()
{
try
{
Class.forName("org.apache.cassandra.cql.jdbc.CassandraDriver");
Connection con = DriverManager.getConnection("jdbc:cassandra://192.168.1.32:9160/temp");
String qry = "CREATE TABLE users(user_name varchar," +
"password varchar," +
"gender varchar," +
"session_token varchar," +
"birth_year bigint," +
"PRIMARY KEY (user_name)" +
")";
Statement smt = con.createStatement();
smt.executeUpdate(qry);
System.out.println("TABLE(column family) is created");
con.close();
}
catch(Exception e)
{
System.out.println(" : " + e.getMessage());
}
}
Here what i got : line 1:132 extraneous input ')' expecting EOF
You're using CQL 2, which does not support that style of primary key declaration. If you want to declare it that way, you should be using CQL 3, which you can accomplish by requesting that version in the connection URL:
DriverManager.getConnection("jdbc:cassandra://192.168.1.32:9160/temp?version=3.0.0");
However, CQL 3 isn't necessary just for this. As Steve Van Opstal suggested, you can simply put the PRIMARY KEY marker with the column definition itself, since you don't have a multi-component primary key.
CREATE TABLE users(
user_name varchar PRIMARY KEY,
password varchar,
gender varchar,
session_token varchar,
birth_year bigint,
);
CQL 3 is to be generally preferred if your Cassandra supports it, as it is the way forward, but in case you don't want to switch right now, you can make that second change.
I only see two possible problems here.
The query doesn't accept your way of defining the primary key
Try this:
String qry = "CREATE TABLE users(user_name varchar PRIMARY KEY," +
"password varchar," +
"gender varchar," +
"session_token varchar," +
"birth_year bigint"
")";
The query doesn't accept varchar's as primary key
Try this:
String qry = "CREATE TABLE users(user_id int" +
"user_name varchar," +
"password varchar," +
"gender varchar," +
"session_token varchar," +
"birth_year bigint," +
"PRIMARY KEY (user_id)" +
")";