An escape string constant is specified by writing the letter E (upper or lower case) just before the opening single quote, e.g., E'foo'. PostgreSQL version 8.0 introduced the dollar quoting feature to make string constants more readable. As you probably understand, apostrophe (otherwise known as semi-quotes or single quotes) and quote symbols are used in Postgres and many programming languages to delineate text strings and string-based commands. Summary: in this tutorial, you will learn about PostgreSQL foreign key and how to add foreign keys to tables using foreign key constraints.. Introduction to PostgreSQL Foreign Key Constraint. What is happening is that Postgres is seeing the sql string as an identifier and is looking for a column of that name. (When continuing an escape string constant across lines, write E only before the first opening quote.) You could write your function definition with single-quotes just as well. The str_1, str_2, etc., are strings or any arguments that can be converted into strings.. replacing single quotes. The problem arises when the string constant contains many single quotes and backslashes. Won't help --- that will match a field that is empty and *doesn't* have quotes. Input is of form 'ppp','aaa','bbb' I want it to be stripped of quotes to become ppp,aaa,bbb escaping the quote would work but it means I will have to do some... PostgreSQL › PostgreSQL - general > I suspect the solution is probably simple; yet, I can't get i I think you need two single quotes around the embedded sql string. Responses Re: Why are quotes required around table / column names in SQL statements? Dollar-quoting is a PostgreSQL-specific substitute for single quotes to avoid quoting issues inside the function body. One of the questions that invariably arises in these classes has to do with the case sensitivity of the technology in question. 11 Don’t use double quotes in PostgreSQL. PostgreSQL also allows single quotes to be escaped with a backslash (\), so for example the same string could be written 'Dianne\'s horse'. The CONCAT_WS function returns a combined string that is the combination of str_1, str_2, etc., separated by the separator.. PostgreSQL CONCAT_WS function example. at 2001-04-03 01:25:45 from Lee Harr >> >> All of the values within the CSV are surrounded with quotation marks. You could write your function definition with single-quotes just as well. > Have you tried WITH NULL AS ''? into PGSQL and I find the quotes very distracting. Bruce Momjian <[hidden email]> writes: > Walter wrote: >> I have a problem using the copy command on a CSV file. PostgreSQL QUOTE_IDENT() function with Example : The PostgreSQL quote_ident function is used to make a given string with suitably double quoted, so as it can be used like an identifier in an sql statement string if required. A foreign key is a column or a group of columns in a table that reference the primary key of another table.. So >> a null value for a field looks like "" > It should be ,, for NULL. I spend a large proportion of my time teaching classes in a variety of open-source technologies — specifically, Ruby, Python, PostgreSQL, and Git. PostgreSQL also accepts “ escape ” string constants, which are an extension to the SQL standard. Doubling every single quote and backslash makes the string constant more difficult to read and maintain. The separator is a string that separates all arguments in the result string.. For example, a typical WHERE clause may look like WHERE t_name = 'database'. The table that contains the foreign key is called the referencing table or child table.