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PostgreSQL documentation

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copy the contents of a file into a table column. First load the file into a

variable and then proceed as above.

<programlisting>

testdb=&gt; <userinput>\set content '\'' `cat my_file.txt` '\''</userinput>

testdb=&gt; <userinput>\set content '''' `cat my_file.txt` ''''</userinput>

testdb=&gt; <userinput>INSERT INTO my_table VALUES (:content);</userinput>

</programlisting>

One possible problem with this approach is that <filename>my_file.txt</filename>

might contain single quotes. These need to be escaped so that

they don't cause a syntax error when the second line is processed. This

could be done with the program <command>sed</command>:

<programlisting>

testdb=&gt; <userinput>\set content '\'' `sed -e "s/'/\\\\\\'/g" &lt; my_file.txt` '\''</userinput>

testdb=&gt; <userinput>\set content '''' `sed -e "s/'/\\\\''/g" &lt; my_file.txt` ''''</userinput>

</programlisting>

Observe the correct number of backslashes (6)! It works

this way: After <application>psql</application> has parsed this

line, it passes <literal>sed -e "s/'/\\\'/g" &lt; my_file.txt</literal>

line, it passes <literal>sed -e "s/'/\\''/g" &lt; my_file.txt</literal>

to the shell. The shell will do its own thing inside the double

quotes and execute <command>sed</command> with the arguments

<literal>-e</literal> and <literal>s/'/\\'/g</literal>. When

<literal>-e</literal> and <literal>s/'/''/g</literal>. When

<command>sed</command> parses this it will replace the two

backslashes with a single one and then do the substitution. Perhaps

at one point you thought it was great that all Unix commands use the

{quote}{return LEXRES_OK; }

{xqdouble}{emit("'",1); }

"\\n"{appendPQExpBufferChar(output_buf,'\n'); }

"\\t"{appendPQExpBufferChar(output_buf,'\t'); }

"\\b"{appendPQExpBufferChar(output_buf,'\b'); }