I am trying to learn the best way to write queries. I also understand the importance of being consistent. Until now, I have randomly used single quotes, double quotes, and backticks without any real thought.
Example:
$query = 'INSERT INTO table (id, col1, col2) VALUES (NULL, val1, val2)';
Also, in the above example, consider that table, col1, val1, etc. may be variables.
What is the standard for this? What do you do?
I've been reading answers to similar questions on here for about 20 minutes, but it seems like there is no definitive answer to this question.
Backticks are to be used for table and column identifiers, but are only necessary when the identifier is a MySQL reserved keyword, or when the identifier contains whitespace characters or characters beyond a limited set (see below) It is often recommended to avoid using reserved keywords as column or table identifiers when possible, avoiding the quoting issue.
Single quotes should be used for string values like in the VALUES() list. Double quotes are supported by MySQL for string values as well, but single quotes are more widely accepted by other RDBMS, so it is a good habit to use single quotes instead of double.
MySQL also expects DATE and DATETIME literal values to be single-quoted as strings like '2001-01-01 00:00:00'. Consult the Date and Time Literals documentation for more details, in particular alternatives to using the hyphen - as a segment delimiter in date strings.
So using your example, I would double-quote the PHP string and use single quotes on the values 'val1', 'val2'. NULL is a MySQL keyword, and a special (non)-value, and is therefore unquoted.
None of these table or column identifiers are reserved words or make use of characters requiring quoting, but I've quoted them anyway with backticks (more on this later...).
Functions native to the RDBMS (for example, NOW() in MySQL) should not be quoted, although their arguments are subject to the same string or identifier quoting rules already mentioned.
Backtick (`)
table & column ───────┬─────┬──┬──┬──┬────┬──┬────┬──┬────┬──┬───────┐
↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓
$query = "INSERT INTO `table` (`id`, `col1`, `col2`, `date`, `updated`)
VALUES (NULL, 'val1', 'val2', '2001-01-01', NOW())";
↑↑↑↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑↑↑↑↑
Unquoted keyword ─────┴┴┴┘ │ │ │ │ │ │ │││││
Single-quoted (') strings ───────────┴────┴──┴────┘ │ │ │││││
Single-quoted (') DATE ───────────────────────────┴──────────┘ │││││
Unquoted function ─────────────────────────────────────────┴┴┴┴┘
Variable interpolation
The quoting patterns for variables do not change, although if you intend to interpolate the variables directly in a string, it must be double-quoted in PHP. Just make sure that you have properly escaped the variables for use in SQL. (It is recommended to use an API supporting prepared statements instead, as protection against SQL injection).
// Same thing with some variable replacements
// Here, a variable table name $table is backtick-quoted, and variables
// in the VALUES list are single-quoted
$query = "INSERT INTO `$table` (`id`, `col1`, `col2`, `date`) VALUES (NULL, '$val1', '$val2', '$date')";
Prepared statements
When working with prepared statements, consult the documentation to determine whether or not the statement's placeholders must be quoted. The most popular APIs available in PHP, PDO and MySQLi, expect unquoted placeholders, as do most prepared statement APIs in other languages:
// PDO example with named parameters, unquoted
$query = "INSERT INTO `table` (`id`, `col1`, `col2`, `date`) VALUES (:id, :col1, :col2, :date)";
// MySQLi example with ? parameters, unquoted
$query = "INSERT INTO `table` (`id`, `col1`, `col2`, `date`) VALUES (?, ?, ?, ?)";
Characters requring backtick quoting in identifiers:
According to MySQL documentation, you do not need to quote (backtick) identifiers using the following character set:
ASCII: [0-9,a-z,A-Z$_] (basic Latin letters, digits 0-9, dollar, underscore)
You can use characters beyond that set as table or column identifiers, including whitespace for example, but then you must quote (backtick) them.
Also, although numbers are valid characters for identifiers, identifiers cannot consist solely of numbers. If they do they must be wrapped in backticks.
There are two types of quotes in MySQL:
' for enclosing string literals
` for enclosing identifiers such as table and column names
And then there is " which is a special case. It could be used for one of above-mentioned purposes at a time depending on MySQL server's sql_mode:
By default the " character can be used to enclose string literals just like '
In ANSI_QUOTES mode the " character can be used to enclose identifiers just like `
The following query will produce different results (or errors) depending on SQL mode:
SELECT "column" FROM table WHERE foo = "bar"
ANSI_QUOTES disabled
The query will select the string literal "column" where column foo is equal to string "bar"
ANSI_QUOTES enabled
The query will select the column column where column foo is equal to column bar
When to use what
I suggest that you avoid using " so that your code becomes independent of SQL modes
Always quote identifiers since it is a good practice (quite a few questions on SO discuss this)
(There are good answers above regarding the SQL nature of your question, but this may also be relevant if you are new to PHP.)
Perhaps it is important to mention that PHP handles single and double quoted strings differently...
Single-quoted strings are 'literals' and are pretty much WYSIWYG strings. Double-quoted strings are interpreted by PHP for possible variable-substitution (backticks in PHP are not exactly strings; they execute a command in the shell and return the result).
Examples:
$foo = "bar";
echo 'there is a $foo'; // There is a $foo
echo "there is a $foo"; // There is a bar
echo `ls -l`; // ... a directory list
Backticks are generally used to indicate an identifier and as well be safe from accidentally using the Reserved Keywords.
For example:
Use `database`;
Here the backticks will help the server to understand that the database is in fact the name of the database, not the database identifier.
Same can be done for the table names and field names. This is a very good habit if you wrap your database identifier with backticks.
Check this answer to understand more about backticks.
Now about Double quotes & Single Quotes (Michael has already mentioned that).
But, to define a value you have to use either single or double quotes. Lets see another example.
INSERT INTO `tablename` (`id, `title`) VALUES ( NULL, title1);
Here I have deliberately forgotten to wrap the title1 with quotes. Now the server will take the title1 as a column name (i.e. an identifier). So, to indicate that it's a value you have to use either double or single quotes.
INSERT INTO `tablename` (`id, `title`) VALUES ( NULL, 'title1');
Now, in combination with PHP, double quotes and single quotes make your query writing time much easier. Let's see a modified version of the query in your question.
$query = "INSERT INTO `table` (`id`, `col1`, `col2`) VALUES (NULL, '$val1', '$val2')";
Now, using double quotes in the PHP, you will make the variables $val1, and $val2 to use their values thus creating a perfectly valid query. Like
$val1 = "my value 1";
$val2 = "my value 2";
$query = "INSERT INTO `table` (`id`, `col1`, `col2`) VALUES (NULL, '$val1', '$val2')";
will make
INSERT INTO `table` (`id`, `col1`, `col2`) VALUES (NULL, 'my value 1', 'my value 2')
In MySQL, these symbols are used to delimit a query ` ," ,' and () .
" or ' are used for enclosing string-like values "26-01-2014 00:00:00" or '26-01-2014 00:00:00' . These symbols are only for strings, not aggregate functions like now, sum, or max.
` is used for enclosing table or column names, e.g. select `column_name` from `table_name` where id='2'
( and ) simply enclose parts of a query e.g. select `column_name` from `table_name` where (id='2' and gender='male') or name='rakesh' .
There has been many helpful answers here, generally culminating into two points.
BACKTICKS(`) are used around identifier names.
SINGLE QUOTES(') are used around values.
AND as #MichaelBerkowski said
Backticks are to be used for table and column identifiers, but are
only necessary when the identifier is a MySQL reserved keyword, or
when the identifier contains whitespace characters or characters
beyond a limited set (see below) It is often recommended to avoid
using reserved keywords as column or table identifiers when possible,
avoiding the quoting issue.
There is a case though where an identifier can neither be a reserved keyword or contain whitespace or characters beyond limited set but necessarily require backticks around them.
EXAMPLE
123E10 is a valid identifier name but also a valid INTEGER literal.
[Without going into detail how you would get such an identifier name], Suppose I want to create a temporary table named 123456e6.
No ERROR on backticks.
DB [XXX]> create temporary table `123456e6` (`id` char (8));
Query OK, 0 rows affected (0.03 sec)
ERROR when not using backticks.
DB [XXX]> create temporary table 123451e6 (`id` char (8));
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '123451e6 (`id` char (8))' at line 1
However, 123451a6 is a perfectly fine identifier name (without back ticks).
DB [XXX]> create temporary table 123451a6 (`id` char (8));
Query OK, 0 rows affected (0.03 sec)
This is completely because 1234156e6 is also an exponential number.
The string literals in MySQL and PHP are the same.
A string is a sequence of bytes or characters, enclosed within either
single quote (“'”) or double quote (“"”) characters.
So if your string contains single quotes, then you could use double quotes to quote the string, or if it contains double quotes, then you could use single quotes to quote the string. But if your string contains both single quotes and double quotes, you need to escape the one that used to quote the string.
Mostly, we use single quotes for an SQL string value, so we need to use double quotes for a PHP string.
$query = "INSERT INTO table (id, col1, col2) VALUES (NULL, 'val1', 'val2')";
And you could use a variable in PHP's double-quoted string:
$query = "INSERT INTO table (id, col1, col2) VALUES (NULL, '$val1', '$val2')";
But if $val1 or $val2 contains single quotes, that will make your SQL be wrong. So you need to escape it before it is used in sql; that is what mysql_real_escape_string is for. (Although a prepared statement is better.)
In combination of PHP and MySQL, double quotes and single quotes make your query-writing time so much easier.
$query = "INSERT INTO `table` (`id`, `col1`, `col2`) VALUES (NULL, '$val1', '$val2')";
Now, suppose you are using a direct post variable into the MySQL query then, use it this way:
$query = "INSERT INTO `table` (`id`, `name`, `email`) VALUES (' ".$_POST['id']." ', ' ".$_POST['name']." ', ' ".$_POST['email']." ')";
This is the best practice for using PHP variables into MySQL.
If table cols and values are variables then there are two ways:
With double quotes "" the complete query:
$query = "INSERT INTO $table_name (id, $col1, $col2)
VALUES (NULL, '$val1', '$val2')";
Or
$query = "INSERT INTO ".$table_name." (id, ".$col1.", ".$col2.")
VALUES (NULL, '".$val1."', '".$val2."')";
With single quotes '':
$query = 'INSERT INTO '.$table_name.' (id, '.$col1.', '.$col2.')
VALUES (NULL, '.$val1.', '.$val2.')';
Use back ticks `` when a column/value name is similar to a MySQL reserved keyword.
Note: If you are denoting a column name with a table name then use back ticks like this:
`table_name`. `column_name` <-- Note: exclude . from back ticks.
Single quotes should be used for string values like in the VALUES() list.
Backticks are generally used to indicate an identifier and as well be safe from accidentally using the reserved keywords.
In combination of PHP and MySQL, double quotes and single quotes make your query writing time so much easier.
Besides all of the (well-explained) answers, there hasn't been the following mentioned and I visit this Q&A quite often.
In a nutshell; MySQL thinks you want to do math on its own table/column and interprets hyphens such as "e-mail" as e minus mail.
Disclaimer: So I thought I would add this as an "FYI" type of answer for those who are completely new to working with databases and who may not understand the technical terms described already.
SQL servers and MySQL, PostgreySQL, Oracle don't understand double quotes("). Thus your query should be free from double quotes(") and should only use single quotes(').
Back-trip(`) is optional to use in SQL and is used for table name, db name and column names.
If you are trying to write query in your back-end to call MySQL then you can use double quote(") or single quotes(') to assign query to a variable like:
let query = "select id, name from accounts";
//Or
let query = 'select id, name from accounts';
If ther's a where statement in your query and/or trying to insert a value and/or an update of value which is string use single quote(') for these values like:
let querySelect = "select id, name from accounts where name = 'John'";
let queryUpdate = "update accounts set name = 'John' where id = 8";
let queryInsert = "insert into accounts(name) values('John')";
//Please not that double quotes are only to be used in assigning string to our variable not in the query
//All these below will generate error
let querySelect = 'select id, name from accounts where name = "John"';
let queryUpdate = 'update accounts set name = "John" where id = 8';
let queryInsert = 'insert into accounts(name) values("John")';
//As MySQL or any SQL doesn't understand double quotes("), these all will generate error.
If you want to stay out of this confusion when to use double quotes(") and single quotes('), would recommend to stick with single quotes(') this will include backslash() like:
let query = 'select is, name from accounts where name = \'John\'';
Problem with double(") or single(') quotes arise when we had to assign some value dynamic and perform some string concatenation like:
let query = "select id, name from accounts where name = " + fName + " " + lName;
//This will generate error as it must be like name = 'John Smith' for SQL
//However our statement made it like name = John Smith
//In order to resolve such errors use
let query = "select id, name from accounts where name = '" + fName + " " + lName + "'";
//Or using backslash(\)
let query = 'select id, name from accounts where name = \'' + fName + ' ' + lName + '\'';
If need further clearance do follow quotes in JavaScript
It is sometimes useful to not use quotes... because this can highlight issues in the code generating the query... For example:
Where x and y are should always be integers...
SELECT * FROM table WHERE x= AND y=0
Is a SQL syntax error... a little lazy but can be useful...
Related
What is the correct SQL syntax to insert a value with an apostrophe in it?
Insert into Person
(First, Last)
Values
'Joe',
'O'Brien'
I keep getting an error as I think the apostrophe after the O is the ending tag for the value.
Escape the apostrophe (i.e. double-up the single quote character) in your SQL:
INSERT INTO Person
(First, Last)
VALUES
('Joe', 'O''Brien')
/\
right here
The same applies to SELECT queries:
SELECT First, Last FROM Person WHERE Last = 'O''Brien'
The apostrophe, or single quote, is a special character in SQL that specifies the beginning and end of string data. This means that to use it as part of your literal string data you need to escape the special character. With a single quote this is typically accomplished by doubling your quote. (Two single quote characters, not double-quote instead of a single quote.)
Note: You should only ever worry about this issue when you manually edit data via a raw SQL interface since writing queries outside of development and testing should be a rare occurrence. In code there are techniques and frameworks (depending on your stack) that take care of escaping special characters, SQL injection, etc.
You just have to double up on the single quotes...
insert into Person (First, Last)
values ('Joe', 'O''Brien')
You need to escape the apostrophe. In T-SQL this is with a double apostrophe, so your insert statement becomes:
Insert into Person
(First, Last)
Values
'Joe', 'O''Brien'
Because a single quote is used for indicating the start and end of a string; you need to escape it.
The short answer is to use two single quotes - '' - in order for an SQL database to store the value as '.
Look at using REPLACE to sanitize incoming values:
Oracle REPLACE
SQL Server REPLACE
MySQL REPLACE
PostgreSQL REPLACE
You want to check for '''', and replace them if they exist in the string with '''''' in order to escape the lone single quote.
Single quotes are escaped by doubling them up,
The following SQL illustrates this functionality.
declare #person TABLE (
[First] nvarchar(200),
[Last] nvarchar(200)
)
insert into #person
(First, Last)
values
('Joe', 'O''Brien')
select * from #person
Results
First | Last
===================
Joe | O'Brien
eduffy had a good idea. He just got it backwards in his code example. Either in JavaScript or in SQLite you can replace the apostrophe with the accent symbol.
He (accidentally I am sure) placed the accent symbol as the delimiter for the string instead of replacing the apostrophe in O'Brian. This is in fact a terrifically simple solution for most cases.
The apostrophe character can be inserted by calling the CHAR function with the apostrophe's ASCII table lookup value, 39. The string values can then be concatenated together with a concatenate operator.
Insert into Person
(First, Last)
Values
'Joe',
concat('O',char(39),'Brien')
use double quotation marks around the values.
insert into Person (First, Last) Values("Joe","O'Brien")
Another way of escaping the apostrophe is to write a string literal:
insert into Person (First, Last) values (q'[Joe]', q'[O'Brien]')
This is a better approach, because:
Imagine you have an Excel list with 1000's of names you want to upload to your database. You may simply create a formula to generate 1000's of INSERT statements with your cell contents instead of looking manually for apostrophes.
It works for other escape characters too. For example loading a Regex pattern value, i.e. ^( *)(P|N)?( *)|( *)((<|>)\d\d?)?( *)|( )(((?i)(in|not in)(?-i) ?(('[^']+')(, ?'[^']+'))))?( *)$ into a table.
If it is static text, you can use two single quote instead of one as below:
DEC #text = 'Khabir''s Account'
See after Khabir there are two single quote ('')
If your text is not static and it is passed in Store procedure parameter then
REPLACE(#text, '''', '')
This is how my data as API response looks like, which I want to store in the MYSQL database. It contains Quotes, HTML Code , etc.
Example:-
{
rewardName: "Cabela's eGiftCard $25.00",
shortDescription: '<p>adidas gift cards can be redeemed in over 150 adidas Sport Performance, adidas Originals, or adidas Outlet stores in the US, as well as online at adidas.com.</p>
terms: '<p>adidas Gift Cards may be redeemed for merchandise on adidas.com and in adidas Sport Performance, adidas Originals, and adidas Outlet stores in the United States.'
}
SOLUTION
CREATE TABLE `brand` (
`reward_name` varchar(2048),
`short_description` varchar(2048),
`terms` varchar(2048),
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=latin1;
While inserting , In followed JSON.stringify()
let brandDetails= {
rewardName: JSON.stringify(obj.rewardName),
shortDescription: JSON.stringify(obj.shortDescription),
term: JSON.stringify(obj.term),
}
Above is the JSON object and below is the SQL Query that insert data into MySQL.
let query = `INSERT INTO brand (reward_name, short_description, terms)
VALUES (${brandDetails.rewardName},
(${brandDetails.shortDescription}, ${brandDetails.terms})`;
Its worked....
Use a backtick (on the ~ key) instead;
`O'Brien`
the solution provided is not working fine, since it ads the string with two single quote in database, the simplest way is to use anti back slash before the apostrophe (single quote).
Insert into Person (First, Last) Values 'Joe', 'O\'Brien'
I'm using Oracle 10g and I'm having a problem inserting a string with double quotes into a table. This is my statement
INSERT INTO USERS (ID, NAME, USERNAME) VALUES (NULL, "tes", "hello");
The query above fails with the error "Oracle column not allowed here".
If I change double quotes to single quotes, as below the statement is successful.
INSERT INTO USERS (ID, NAME, USERNAME) VALUES (NULL, 'tes', 'hello');
But, I want to insert the double quotes into the table.
Is it possible to have double quote in strings in an insert statement? I don't want to use REPLACE() because my query is automatically generated from an array.
A double quote is used to denote a quoted identifier, i.e. an object name that does not solely consist of alpha-numeric characters, $ and #. As an aside, it's recommended that you do not use quoted identifiers. This is the reason for your original ORA-00984 error. Oracle is assuming that "tes" is a column, not a string, and you can't use a column name in the VALUES clause of an INSERT statement, as explained in the error message.
In order to insert the string "tes" into a table you need to ensure that it is quoted correctly:
Character literals are enclosed in single quotation marks so that the database can distinguish them from schema object names.
Any character can be part of a string so in order to insert a double quote into a table you need to enclose it within single quotes.
insert into users (id, name, username)
values (null, '"tes"', '"hello"');
Here's a SQL Fiddle to demonstrate.
One additional thing to note. You state that this query is automatically generated, which means you may be vulnerable to SQL injection. I would highly recommend reading about bind variables in Guarding Against SQL Injection.
It is possible. In Oracle, you quote string literals using single quotes.
If you want to insert test into the database then you must quote that as 'test'.
INSERT INTO USERS (NAME) VALUES ('test');
If you want to insert "test" into the database then you must quote that as '"test"'.
INSERT INTO USERS (NAME) VALUES ('"test"');
Try wrapping the values inside single quotes.
INSERT INTO USERS (ID, NAME, USERNAME) VALUES (NULL, '"tes"', '"hello"');
I have a table companies, which has two columns named name and address. By running the following code, new data are inserted into the table:
my_name = "my company name"
my_address = "ABC"
query = "INSERT INTO companies (name,address) VALUES ('#{my_name}','#{my_address}');"
ActiveRecord::Base.connection.execute(query);
If I change my_name value from "my company name" to "John's company", I will get a syntax error. This is because the query becomes:
"INSERT INTO companies (name,address) VALUES ('John's company','ABC');"
and 'John's company' has a single quotation mark within it.
Given that I have already used double quotation mark for the query string definition, how can I get rid of this error regarding the single quotation mark in my value?
If you must do it this way then use the quote method on the connection object:
quote(value, column = nil)
Quotes the column value to help prevent SQL injection attacks.
So something like this:
my_name = ActiveRecord::Base.connection.quote("John O'Neil")
my_address = ActiveRecord::Base.connection.quote("R'lyeh")
query = "INSERT INTO companies (name,address) VALUES (#{my_name}, #{my_address})"
ActiveRecord::Base.connection.execute(query);
Never ever try to handle your own quoting. And don't try to use double quotes for quoting an SQL string literal, that's what single quotes are for; double quotes are for quoting identifiers (such as table and column names) in most databases but MySQL uses backticks for that.
What are the various ways to ESCAPE single quotes(') in the SQL LIKE command?
One way is to put two single quotes whenever you have to escape a single quote.
Can you people suggest something?
Databases: SQL Server 2005 and Oracle 10g
You already have the answer. You have to use two single quotes:
select * from table where field like '%''something''%'
Two single quotes is the best solution.
Alternatively, you can use a CHAR(39) to represent a single quote character.
UPDATE Employee SET LastName = 'O' + CHAR(39) + 'Brien'
WHERE ID=1;
The best way is to bind the parameter with ADO or ADO.NET.
Like (example in C# with ADO.NET):
SqlCommand x = new SqlCommand(sqlConnection, #"select * from table where col like '%'+#para1+'%'");
x.parameters.add(new SqlParameter("#para1",sqltype.varchar,100)).value = "this is a' test";
In SQL Server 2005 you escape a single quote (') with a double single quote ('') if you do not want to bind:
select * from table where col like '%this is a'' test%'
If you want to search the value Allen O'Dea following is the query.
SELECT * FROM [TABLE] WHERE [COLUMN] LIKE '%Allen O''Dea%'
This query works perfectly.
There is also the "Q-quote" method:
select * from mytable where text like q'#%Here's some text%#';
This is available since Oracle 10.2.
I used a '#' character as the quote delimiter, but you can use pretty much any character that won't appear in the string (there are a few exceptions, such as the space character).
In a simple example like that above I probably wouldn't do this. I'd just double up the single quotes, but it does come in handy when building large dynamic SQL statements that include lots of string literals.
We need to store a select statement in a table
select * from table where col = 'col'
But the single quotes messes the insert statement up.
Is it possible to do this somehow?
From Oracle 10G on there is an alternative to doubling up the single quotes:
insert into mytable (mycol) values (q'"select * from table where col = 'col'"');
I used a double-quote character ("), but you can specify a different one e.g.:
insert into mytable (mycol) values (q'#select * from table where col = 'col'#');
The syntax of the literal is:
q'<special character><your string><special character>'
It isn't obviously more readable in a small example like this, but it pays off with large quantities of text e.g.
insert into mytable (mycol) values (
q'"select empno, ename, 'Hello' message
from emp
where job = 'Manager'
and name like 'K%'"'
);
How are you performing the insert? If you are using any sort of provider on the front end, then it should format the string for you so that quotes aren't an issue.
Basically, create a parameterized query and assign the value of the SQL statement to the parameter class instance, and let the db layer take care of it for you.
you can either use two quotes '' to represent a single quote ' or (with 10g+) you can also use a new notation:
SQL> select ' ''foo'' ' txt from dual;
TXT
-------
'foo'
SQL> select q'$ 'bar' $' txt from dual;
TXT
-------
'bar'
If you are using a programming language such as JAVA or C#, you can use prepared (parametrized) statements to put your values in and retrieve them.
If you are in SQLPlus you can escape the apostrophe like this:
insert into my_sql_table (sql_command)
values ('select * from table where col = ''col''');
Single quotes are escaped by duplicating them:
INSERT INTO foo (sql) VALUES ('select * from table where col = ''col''')
However, most database libraries provide bind parameters so you don't need to care about these details:
INSERT INTO foo (sql) VALUES (:sql)
... and then you assign a value to :sql.
Don't store SQL statements in a database!!
Store SQL Views in a database. Put them in a schema if you have to make them cleaner. There is nothing good that will happen ever if you store SQL Statements in a database, short of logging this is categorically a bad idea.
Also if you're using 10g, and you must do this: do it right! Per the FAQ
Use the 10g Quoting mechanism:
Syntax
q'[QUOTE_CHAR]Text[QUOTE_CHAR]'
Make sure that the QUOTE_CHAR doesnt exist in the text.
SELECT q'{This is Orafaq's 'quoted' text field}' FROM DUAL;