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Single Quote issue with Oracle 12 C JDBC [duplicate]

I'm having issues dealing with the single quote while using it in a prepared statement in JAVA via Oracle JDBC.
Let's say we have a table Restaurant with a column restaurant_name with 1 value : Jack's Deli
I want to use a simple prepared statement query like this:
String result = "Jack\'\'s Deli"
String sqlStatement = "select * from Restaurant where restauraunt_name like ? escape '\\' ";
PreparedStatement pStmt = conn.prepareStatement(sqlStatement);
pstmt.setString(1, result);
The result shows 0 returned values, however when I directly search the query in the database (ORACLE) it works fine and retrieves the result. (Oracle uses two single quotes as an escape for the first)
I am thinking that the value is not being passed properly to the database. Or there is some other formatting issue.

The point of prepared statements is that you don't need any escaping.
.setString(1, "Jack's Deli") will get it done.

Dynamic column name using prepared statement + sql query with variable containing 's

My query
attributes.replace(" ' ", "");
//also used SET "+attributes+"
String sql;
sql = "UPDATE diseaseinfo"
+ " SET ?=?"
+ "WHERE companyname = 'mycom' && diseaseName =?";
PreparedStatement preparedStmt = connects.prepareStatement(sql);
preparedStmt.setString(1, attributes);
preparedStmt.setString(2, attrData);
preparedStmt.setString(3, medname);
System.out.println(preparedStmt);
it is giving me an error because query set the column name in string so it become like this on causes
UPDATE diseaseinfo SET 'causes'='abc' WHERE companyname = 'mycom' and diseaseName ='fever'
and through this question I get to know that I can't add dynamic column by prepared statement: https://stackoverflow.com/a/3136049/7794329
Now, the real question comes up: suppose if I will use a simple update query like in this question: jdbc dymanic sql query with variable containg 's
It says you can't enter value with 's in your simple sql query because it will again make the query syntactical error for example :
SELECT * FROM diseaseinfo WHERE diseaseName = 'Adult Still's disease' AND name = 'add';
Here it wont execute because of ' 's on 'Adult Still's
Then it won't work with simple query. What should I do now? What to use? To set dynamic column with taking care of 's in the query.
I am not worried about SQL injection because i am working on local. And I just want my query to be executed.

Right. We can't supply identifiers as bind parameters. The name of the column has to be part of the SQL text.
We can dynamically incorporate the name of the column into the SQL text with something like this:
sql = "UPDATE diseaseinfo"
+ " SET `" + colname + "` = ?"
+ " WHERE companyname = 'mycom' AND diseaseName = ?";
And supply values for the two remaining bind parameters
preparedStmt.setString(1, attrData);
preparedStmt.setString(2, medname);
And you are absolutely correct about being concerned about SQL Injection.
Supplied as bind values, single quotes in the values of attrData and medname won't be an issue, in terms of SQL Injection.
But the example I've provided is vulnerable through incorporating the colname variable into the SQL text, if we don't have some guaranteed that colname is "safe" to include in the statement.
So we need to make the assignment of a value to colname "safe".
Several approaches we can use do that. The most secure would be a "whitelist" approach. The code can ensure that only specific allowed "safe" values get assigned to colname, before colname gets included into the SQL text.
As a simple example:
String colname;
if (attributes.equals("someexpectedvalue") {
colname = "columnname_to_be_used";
} else if (attributes.equals("someothervalid") {
colname = "valid_columname";
} else {
// unexpected/unsupported attributes value so
// handle condition or throw an exception
}
A more flexible approach is to ensure that a backtick character doesn't appear in colname. In the example, the value of colname is being escaped by enclosing it in backticks. So, as long as a backtick character doesn't appear in colname, we will prevent a supplied value from being interpreted as anything other than as an identifier.
For a more generic (and complicated) approach to using hardcoded backtick characters, we could consider making use the supportsQuotedIdentifiers and getIdentifierQuoteString methods of java.sql.DatabaseMetaData class.
(In the OP code, we don't see the datatype of contents of attributes. We see a call to a method named replace, and the arguments that are supplied to that. Assuming that attributes is a String, and that's supposed to be a column name, it's not at all clear why we would have "space single quote space" in the string, or why we need to remove that. Other than this mention, this answer doesn't address that.)

Java PreparedStatement SQL syntax error [duplicate]

This question already has answers here:
Java PreparedStatement complaining about SQL syntax on execute()
(6 answers)
Closed 6 years ago.
This is a really weird error that only started appearing today. When I use a prepared statement with ? for parameters, I get an error, but when I use it without parameters, it works just fine.
Here is the error-causing code:
String table = "files";
Connection conn = DriverManager.getConnection(DB_URL, DB_USER, DB_PASS);
PreparedStatement prep = conn.prepareStatement("SELECT * FROM ?");
prep.setString(1, table);
ResultSet rs = prep.executeQuery();
while(rs.next()) {
System.out.println(rs.getString("file_name"));
}
This produces the following error:
Exception in thread "main" 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 ''files'' at line 1
Also, changing it to the following works just fine:
String table = "files";
Connection conn = DriverManager.getConnection(DB_URL, DB_USER, DB_PASS);
PreparedStatement prep = conn.prepareStatement("SELECT * FROM " + table);
ResultSet rs = prep.executeQuery();
while(rs.next()) {
System.out.println(rs.getString("file_name"));
}
This doesn't seem to be making a whole lot of sense. Any ideas?
Tried it on another table and got more weired results.
This works and logs the admin in correctly:
String sql = "SELECT * FROM " + ADMIN_AUTH_TABLE + " WHERE " + column + " = '" + hashedPassword + "'";
PreparedStatement prepared = connection.prepareStatement(sql);
The following doesn't cause errors, but returns a message saying that the password entered is incorrect (it's correct - I double triple checked).
String sql = "SELECT * FROM " + ADMIN_AUTH_TABLE + " WHERE ? = ?";
PreparedStatement prepared = connection.prepareStatement(sql);
prepared.setString(1, column);
prepared.setString(2, hashedPassword);
Got it: use ? for values.
Also, the answer here helped.

Bind parameters cannot be used for identifiers in the SQL statement. Only values can supplied through bind placeholders.
This will work:
SELECT foo FROM bar WHERE id = ?
This will not work, because the table name is an identifier
SELECT foo FROM ? WHERE id = 2
You can't supply a column name, because column names are also identifiers.
A statement like this will run, but it may not do what you think it does.
SELECT ? AS foo FROM bar WHERE ? = 0
If we supply values of 'foo' for both placeholders, the query will actually be equivalent to a query containing two string literals:
SELECT 'foo' AS foo FROM bar WHERE 'foo' = 0
MySQL will run that statement, because it's a valid statement (if the table bar exists and we have privileges on it.) That query will return every row in bar (because the predicate in the WHERE clause evaluates to TRUE, independent of the contents of the table.. And we get returned the constant string foo.
It doesn't matter one whit that the string foo happens to match the name of column in our table.
This restriction has to do with how the SQL optimizer operates. We don't need to delve into all the details of the steps (briefly: parsing tokens, performing syntax check, performing semantics check, determining query plan, and then the actual execution of the query plan.)
So here's the short story: The values for bind parameters are supplied too late in that process. They are not supplied until that final step, the execution of the query plan.
The optimizer needs to know which tables and columns are being referenced at earlier stages... for the semantics check, and for developing a query plan. The tables and columns have to be identified to the optimizer. Bind placeholders are "unknowns" at the time the table names and column names are needed.
(That short story isn't entirely accurate; don't take all of that as gospel. But it does explain the reason that bind parameters can't be used for identifiers, like table names and column names.)
tl;dr
Given the particular statement you're running, the only value that can be passed in as a bind parameter would be the "hashedPassword" value. Everything else in that statement has to be in the SQL string.
For example, something like this would work:
String sqltext = "SELECT * FROM mytable WHERE mycolumn = ?";
PreparedStatement prepared = connection.prepareStatement(sqltext);
prepared.setString(1, hashedPassword);
To make other parts of the SQL statement "dynamic" (like the table name and column name) you'd have to handle that in the Java code (using string concatenation.) The contents of that string would need to end up like the contents of the sqltext string (in my example) when it's passed to the prepareStatement method.

The parameters of PreparedStatement should be applied only in parameters that can be used in conditional clauses. The table name is not the case here.
If you have a select where the table name can be applied in the conditional clause you can do it, otherwise you can not.

Using datediff in sql jdbc query

I'm attempting to create a JDBC query with the following statement
String query = "SELECT COLUMN1,DATECOLUMN2 FROM tableName +
"where datediff(d,DATECOLUMN2,getdate()) <= 1";
st = conn1.createStatement();
rs = st.executeQuery(query); //receiving error here
I am receiving the following error message
java.sql.SQLException: "d" is not a recognized table hints option. If it is intended as a parameter to a table-valued function or to the CHANGETABLE function, ensure that your database compatibility mode is set to 90.
I'm sure the query isn't recognizing the datediff function for some reason I am not sure why since i was previously using HQL in the same application and retrieving the values.
In an attempt to use an alternative function I used
{fn TIMESTAMPADD( SQL_TSI_DAY, 1, CURRENT_TIMESTAMP)}
but it also failed I later on found that this is only used for Derby Database's
Can someone assist me in using the proper sql function to compare a date with the current date using JDBC

String query = "SELECT COLUMN1,DATECOLUMN2 FROM tableName "+
"where datediff(day,DATECOLUMN2,getdate()) <= 1";

You have a comma before from. Based on the error messages you are running this against SQL server.
String query = "SELECT COLUMN1,DATECOLUMN2 FROM tableName "
+" where datediff(d,DATECOLUMN2,getdate()) <= 1";

The comma after the "d" should be a dot:
where datediff(d.DATECOLUMN2,getdate())
--------------- ^ dot here

The posted snippet doesn't have a closing double quote between tableName and +, but I figure that is just a typo. However, in your real code, where precisely is the double quote? Is it directly after tablename, like this
String query = "SELECT COLUMN1,DATECOLUMN2 FROM tableName" +
or after the space that follows tablename, like this
String query = "SELECT COLUMN1,DATECOLUMN2 FROM tableName "+
It is very likely the former, because in that case the resulting query would look exactly the way as to cause the error you are getting. Take a look at this:
SELECT COLUMN1,DATECOLUMN2 FROM tableNamewhere datediff(d,DATECOLUMN2,getdate()) <= 1
You can see that where merges with the table name and datediff becomes an alias. What follows is interpreted as table hints. (You can specify table hints without WITH in older versions of SQL Server/older compatibility levels.) Consequently, SQL Server stumbles over d, as that is indeed an incorrect table hint.

Oracle DB Query Runs in sqlDev but not in Java Program

I have been messing with Oracle DB queries that run from my JAVA app. I can successfully get them all to run in SQL Developer. But when I am trying to execute them from my JAVA app I usually get UpdatadbleResultSet Error/Exception on certain queries.
Also, sometimes I receive, ExhaustedResultset. As I mention at the bottom I will re work the question to break it down(When I get a chance). I keep editing and pretty soon it'll be a book.
Why is this? I cannot seem to pinpoint the problem.
Some queries run successfully such as:
SELECT table_name
FROM all_tables
SELECT column_name, data_length
FROM all_tab_columns
WHERE table_name = 'mytable'
But when I try and run something like
SELECT length(<myColumnName>)
FROM mytable
I get the updateableResultSetError
I am running my queries as methods called on button clicks (example below).
static void testQuery() {
String query = "SELECT blah from blah"
String length;
ResultSet rs = db.runQuery(query);
Length = rs.getString("length(myCol)")
System.out.println(length);
}
I have also tried while rs.next()
I can only think that for some reason I am unable to get into each table and I can only pull the "bigger" picture.
EDIT: Explained DB Connection
I am connecting using some other jarfiles that have been added to my project.
private static IDriver driver = null;
private static Database db = null;
I then pass in all my connection credentials in a separate method.
private void connectDB(){
driver = new OracleDriver();
db = new Database(driver)
driver.getPassword;
driver.getetc;
driver.getEtc;
}
EDIT:
When I getstacktrace all I am returning is.
Ljava.lang.StatckTraceElement;(assortment of random characters).
I may not be getting stack traces right so someone can fill me in. After all I am offering a bounty.
Also I will edit this question and break it down again when I have the time.

Your problem is that you're trying to update a query that can't be updated, hence the updateable result error. It seems that whoever is creating your database connection or executing your query is creating an updatable result set.
You can't use certain types of select in an updatable result set: you can't use aggregated functions (such as length, min, max), you can't use select * etc.)
For the full list see Result Set Limitations and Downgrade Rules

Try retrieving the value in your select statement via the columnIndex instead of the column name and see if that makes a difference.
Currently, its hard to tell what your db.runQuery() does since that code is not posted.
String query = "SELECT length(myCol) FROM myTable";
String length;
ResultSet rs = db.runQuery(query);
while (rs.next()) {
length = rs.getString(1);
System.out.println(length);
}

I've got an inkling what may be happening here (which would explain why some queries work, and some don't). Accoring to the jdbc ResultSet javadocs, when using the getString() method of the result set, the column label.
the label for the column specified with the SQL AS clause.
If the SQL AS clause was not specified, then the label is the name of the column
As "length(myCol)" is neither a label nor a column name, it may be that it fell over because of that (but without stacktrace it is difficult to say what your problem actually is).
Try
String query = "SELECT length(myCol) AS myCol_len FROM myTable"
ResultSet rs = db.runQuery(query);
String length = rs.getString("myCol_len");
Though are you sure, you didn't want:
int length = rs.getInt("myCol_len");
Alternatively (as written by Kal), you can use the column index to get the data from the result set, which oblivates the need for a SQL AS label:
String query = "SELECT length(myCol) FROM myTable"
ResultSet rs = db.runQuery(query);
String length = rs.getString(1);