I want to get all database table names that ends with _tbl like xyz_tbl, pqr_tbl,etc..
in mysql using java.pls help me.. currently my query retreives all tablename but i jst want table names that ends with _tbl.
My code is...
public List selectTable() {
List tableNameList= new ArrayList();
try {
DatabaseMetaData dbm = c.conn.getMetaData();
String[] types = {"TABLE"};
c.rs = dbm.getTables(null, null, "%", types);
while (c.rs.next()) {
tableNameList.add(c.rs.getString("TABLE_NAME"));
}
} catch(Exception e) {
System.out.println(e.toString());
}
return tableNameList;
}
Did you try using a different table name pattern?
You can try this: -
c.rs = dbm.getTables(null, null, "%_tbl", types);
You can use mysql query
show tables from tablename like '%_tbl';
I am unable to reply to Rohit's post. his answer looks correct.
If you do to JDK documentation for DatabaseMetaData's getTables method following is the signature and documentation comment.
ResultSet getTables(String catalog, String schemaPattern, String tableNamePattern,
String[] types) throws SQLException
Parameters:
catalog - a catalog name; must match the catalog name as it is stored
in the database; "" retrieves those without a catalog; null means that
the catalog name should not be used to narrow the search
schemaPattern
- a schema name pattern; must match the schema name as it is stored in the database; "" retrieves those without a schema; null means that the
schema name should not be used to narrow the search tableNamePattern -
a table name pattern; must match the table name as it is stored in the
database types - a list of table types, which must be from the list of
table types returned from getTableTypes(),to include; null returns all
types
In this case using %_tbl should work.
Use the String.endsWith() method to check if the table name ends with "_tbl".
For example inside your while loop:
while (c.rs.next())
{
String tableName = c.rs.getString("TABLE_NAME");
if(tableName.endsWith("_tbl"))
{
tableNameList.add(c.rs.getString("TABLE_NAME"));
}
}
Related
using sql2o (https://github.com/aaberg/sql2o)
when selecting a VARCHAR column that has trailing spaces (for example "some value ") the return value is "some value"
when selecting from mysql cli the result contains the trailing spaces
cant find any documentation how to prevent this from happening
table:
CREATE TABLE names
(
name VARCHAR(100),
PRIMARY KEY (experiment_key, metric_name)
);
code example:
Sql2o sql2o;
String name = "some name with trailing space ";
try (Connection con = sql2o.open()) {
con.createQuery("INSERT INTO names (name) VALUES(:name)")
.addParameter("name", name)
.executeUpdate();
}
String nameFromDB;
try (Connection con = sql2o.open()) {
nameFromDB = con.createQuery("select name from names")
.executeAndFetchFirst(String.class);
}
if (!nameFromDB.equals(name)){
throw new RuntimeException("where did the trailing spaces go ??? :( ");
}
Think I found your answer in Sql2o.
I believe by using String.class, it is using the StringConverter class to convert your query output into a string. At the very bottom of the StringConverter class is this line:
return val.toString().trim();
Found here
There are three tables <Table 1>, <Table 2> and <Table 3>
My SQL is something like this:
"Select table1.col1, table1.col2, table1.col3, table2.col4, table2.col5, table2.col6,
table3.col7, table3.col8 from Table 1 as table1
LEFT JOIN Table 2 as table2 on (table1.col1 = table2.col4)
LEFT JOIN Table 3 as table3 on (table1.col1 = table3.col8)"
The normal way to get the resultset is:
public List getExportDataList() throws ClassNotFoundException, SQLException {
Connection connect = null;
String url = "jdbc:.....";
String username = "username ";
String password = "password ";
try {
connect = DriverManager.getConnection(url, username, password);
} catch (SQLException ex) {
System.out.println("in exec");
System.out.println(ex.getMessage());
}
List dataList = new ArrayList<>();
PreparedStatement pstmt = connect.prepareStatement(
THE SQL CODE SHOWN ABOVE
}
ResultSet rs = pstmt.executeQuery();
while(rs.next()){
Table1 table1 = new Table1();
table1.setCOL1(rs.getString("col1"));
table1.setCOL2(rs.getString("col2"));
dataList.add(table1);
}
rs.close();
pstmt.close();
connect.close();
return dataList;
}
so that the "dataList" can be used to display the data in Primefaces dataTable.
However, this way only can save the columns in Table1 to the "dataList". I tried to dataList.add(table2) as well as dataList.add(table3) at the same time, but there is an error : "/reportGenerate.xhtml #50,75 value="#{reportData.dateCreated}": The class 'net.picary.model.Liaison' does not have the property 'dateCreated'."
Can someone tell me how to save all the selected columns from the three tables into "dataList"? Or any alternative way to achieve it?
error: "/reportGenerate.xhtml #50,75
value="#{reportData.dateCreated}": The class
'net.picary.model.Liaison' does not have the property 'dateCreated'."
Your problem is not with Query or JDBC, you should to make sure that attribute dateCreated exist in your net.picary.model.Liaison class with getter and setter like this :
private Date dateCreated;
public String name;
public String experience;
public Date getDateCreated() {
return dateCreated;
}
public void setDateCreated(Date dateCreated) {
this.dateCreated = dateCreated;
}
So when your page reportGenerate.xhtml try to load this attribute it not find it, because :
Not exist in your class
It exist but it is private and without getter and setter.
So make sure that your attribute exist and have gtter and setter, this can solve your error.
EDIT
You have two choices :
When you get your result you should to use 3 List of type table1, table2, table3 and fill them in the same loop like this :
List dataList1 = ...;
List dataList2 = ...;
List dataList3 = ...;
while(rs.next()){
table1 = new Table1();
table1.setCOL1(rs.getString("col1"));
...
dataList1.add(table1);
table2 = new Table2();
table2.setCOL1(rs.getString("col1"));
...
dataList2.add(table2);
table3 = new Table3();
table3.setCOL1(rs.getString("col1"));
...
dataList3.add(table3);
}
and in your xhtml page you had to use this three List instead to one
Create a new Object which combine this three Table like this :
class MyObject {
private Table1 table1;
private Table2 table2;
//constructor
//getters and setters
}
Then create a List<MyObject> list = ....; and set information in each table.
Hope you get my point, good luck
First, Check whether column names (col1,col2,col3,..) are with same name in your code in java with all the three db tables (table1,table2,table3).
(ie)
...
Table1 table1 = new Table1();
table1.setCOL1(rs.getString("col1"));
table1.setCOL2(rs.getString("col2"));
dataList.add(table1);
....
In the above code check you have "col1" is in same name with db column in Table1,Table2,Table3.If the column name(s) is different in database and in your code ,add aliases to your MySQL query and match it with same name in your java code.
If the column name matches, then set the column value for your table 2 and 3.
Then, add it to your Datalist.
....
....
table2.setCOL1(rs.getString("col1"));
dataList.add(table2);
....
and so on. Also, check you have added try/catch for your code to avoid exceptions like Nullpointer,SQLException etc.. which may arise during SQL transactions.
I need to use the database Firebird and for this I use the Jaybird 2.2.9.
When I used the MySQL driver, to converter of ResultSet to Object this way:
empresa.setBairro(rs.getString("empresa.bairro")); // (Table.Column)
empresa.setCep(rs.getString("empresa.cep")); // (Table.Column)
empresa.setCidade(rs.getString("empresa.cidade")); // (Table.Column)
But with Jaybird the resultSet don't return rs.getString("Table.Column")
I need this way when I have inner join in SQL.
Anyone help me?
This is my full code
public ContaLivros converterContaLivros(ResultSet rs, Integer linha) throws Exception {
if (rs.first()) {
rs.absolute(linha);
ContaLivros obj = new ContaLivros();
obj.setId(rs.getLong("cad_conta.auto_id"));
obj.setNome(rs.getString("cad_conta.nome"));
if (contain("cad_banco.auto_id", rs)) {
obj.setBancoLivros(converterBancoLivros(rs, linha));
} else {
obj.setBancoLivros(new BancoLivros(rs.getLong("cad_conta.banco"), null, null, null));
}
obj.setAgencia(rs.getInt("cad_conta.agencia"));
obj.setAgenciaDigito(rs.getInt("cad_conta.agencia_digito"));
obj.setConta(rs.getInt("cad_conta.conta"));
obj.setContaDigito(rs.getInt("cad_conta.conta_digito"));
obj.setLimite(rs.getDouble("cad_conta.limite"));
obj.setAtivo(rs.getString("cad_conta.ativo"));
return obj;
} else {
return null;
}
}
You can't. Jaybird retrieves the columns by its label as specified in JDBC 4.2, section 15.2.3. In Firebird the column label is either the original column name, or the AS alias, the table name isn't part of this. The extension of MySQL that you can prefix the table name for disambiguation is non-standard.
Your options are to specify aliases in the query and retrieve by this aliasname, or to process the result set metadata to find the right indexes for each column and retrieve by index instead.
However note that in certain queries (for example UNION), the ResultSetMetaData.getTableName cannot return the table name, as Firebird doesn't "know" it (as you could be applying a UNION to selects from different tables).
The name in jdbc will not have the table in it.
You can either
work with positional parameters ( getString (1); and so on )
Or
define column name alias in your select (select a.name namefroma from tableone a )
Or
simply do rs.getString ("column"); without the table prefix if name is unambigous
As I process each country, how do I add only the languages with matching country id for that country?
private List<String> readCountryLanguages(Statement sqlStatement, List<Country>countries) throws SQLException {
List<String> languages = new ArrayList<>();
for (Country country : countries ) {
ResultSet resultSet = sqlStatement.executeQuery("SELECT language FROM COUNTRY_LANGUAGE");
while (resultSet.next()) {
String language = new String(resultSet.getString("Languages"));
Country obj = new Country(0, language, 0, 0);
obj.getId();
}
}
return languages;
}
Not sure about your table structure of COUNTRY_LANGUAGE but you can update the sql query to something like.
SELECT language FROM COUNTRY_LANGUAGE WHERE country='" + country.getName() + "'
Here I am assuming you have a column "country" in your COUNTRY_LANGUAGE table and country name can be retrieve from Country object by calling Country.getName(). But you can use the exact method from your actual implementation.
return the Country id in a variable when you iterate; you should have something like country.getId();
ResultSet resultSet = sqlStatement.executeQuery("SELECT language FROM COUNTRY_LANGUAGE where id='countryIdVariable'");
change your sql query to be parametized/prepared statement so you can prevent sql injection and also add variable easier instead of having to write variable within single quote in your sql string.
AS menthion by Asura, First of all change your sql query that returns language where contryId is 'something'
then in while loop add each language to languages list object by using add() method like this :
while (resultSet.next()) {
String language = resultSet.getString("Languages");
// add to list
languages.add(language);
}
}
I am having some problems and I'm sure it's something stupid.
So I have a query like
SELECT name, id, xyz FROM table ORDER BY ?
then later down the road setting the ? doing a
ps.setString(1, "xyz");
I am outputting the query and the value of xyz in the console. When I loop through the ResultSet returned from the PreparedStatement the values are not in the correct order. They are in the returned order as if I had left the ORDER BY clause off. When I copy/paste the query and the value into TOAD it runs and comes back correctly.
Any ideas to why the ResultSet is not coming back in the correct order?
The database will see the query as
SELECT name, id, xyz FROM table ORDER BY 'xyz'
That is to say, order by a constant expression (the string 'xyz' in this case). Any order will satisfy that.
? is for parameters, you can't use it to insert column names. The generated statements will look something like
SELECT name, id, xyz FROM table ORDER BY 'xyz'
so that your entries are sorted by the string 'xyz', not by the content of column xyz.
Why not run:
ps.setInteger(1, 3);
Regards.
EDIT: AFAIK Oracle 10g supports it.
PreparedStatement placeholders are not intend for tablenames nor columnnames. They are only intented for actual column values.
You can however use String#format() for this, that's also the way I often do. For example:
private static final String SQL_SELECT_ORDER = "SELECT name, id, xyz FROM table ORDER BY %s";
...
public List<Data> list(boolean ascending) {
String order = ascending ? "ASC" : "DESC";
String sql = String.format(SQL_SELECT_ORDER, order);
...
Another example:
private static final String SQL_SELECT_IN = "SELECT name, id, xyz FROM table WHERE id IN (%s)";
...
public List<Data> list(Set<Long> ids) {
String placeHolders = generatePlaceHolders(ids.size()); // Should return "?,?,?..."
String sql = String.format(SQL_SELECT_IN, placeHolders);
...
DAOUtil.setValues(preparedStatement, ids.toArray());
...
The database will see the query like this
SELECT name, id, xyz FROM table ORDER BY 'xyz'
I think you should add more variable like order_field and order_direction
I assume you have a method like below and I give you an example to solve it
pulbic List<Object> getAllTableWithOrder(String order_field, String order_direction) {
String sql = "select * from table order by ? ?";
//add connection here
PreparedStatement ps = (PreparedStatement) conn.prepareStatement(sql);
ps.setString(1,order_field);
ps.setString(2,order_direction);
logger.info(String.valueOf(ps)); //returns something like: com.mysql.jdbc.JDBC4PreparedStatement#a0ff86: select * from table order by 'id' 'desc'
String sqlb = String.valueOf(ps);
String sqlc = sqlb.replace("'"+order_field+"'", order_field);
String sqld = sqlc.replace("'"+order_direction+"'", order_direction);
String[] normQuery = sqld.split(":");
ResultSet result = conn.createStatement().executeQuery(normQuery[1]);
while(result.next()) {
//iteration
}
}