I am using JDBC with cratedb(which almost uses PSQL protocols). It happens that when I try to execute a query like this
String query = "select * from test where col1='dhruv\'";
It gives me Parser exception.
Caused by: io.crate.shade.org.postgresql.util.PSQLException: Unterminated string literal started at position 39 in SQL select * from test where col1='dhruv\'. Expected char
at io.crate.shade.org.postgresql.core.Parser.checkParsePosition(Parser.java:1310)
at io.crate.shade.org.postgresql.core.Parser.parseSql(Parser.java:1217)
Then on debugging I found that this code in Parser.java of jdbc
else if (c == '\'') {
i0 = i;
i = parseSingleQuotes(p_sql, i, stdStrings);
checkParsePosition(i, len, i0, p_sql, "Unterminated string literal started at position {0} in SQL {1}. Expected ' char");
newsql.append(p_sql, i0, i - i0 + 1);
}
is causing issues. Ad per my understanding they break the values in char arrays and '\''
is conflicting with my \
in the end of the statement.
What I know or tried
I read that people ask to use
prepared statement
since same issue is happening with inserts, but my queries are dynamic so I cannot use thatWe cannot say that its is not possible to insert values like
dhruv\
in database. We can insert directly by console or json files(btw its difficult by java since we need to escape single\
and for db\
is not escape character)Cratedb in latest version has String Literals with C-Style Escape, but just to use this feature I cannot update my whole data base
So is there a way around for it?
++Update
Also found queries like
select * from test where col1='dh\''ruv'
will also not work due to same reason.
++More Update
- So as per my understanding
select * from workkards where w_number='dhruv\\'
, at run time sees it asselect * from workkards where w_number='dhruv\'
- In
'dhruv\'
, now backslash is escaping quote , so quote is escaped - So crate jdbc parser says unterminated string since
'
is escaped
- In
Way around on which I am working
- I am replacing
\
in java code with\
i.e backslash and space, The user cannot see any difference since space is not visible
if(value.contains("\\") ){
return value.replace("\\", "\\ ");
}
- Somewhat like above, seems to be working find as I am able to insert value, but there is one problem
- The value is stored in database with trailing space, so there is issue in searching this value
- We can apply the same logic to search query so it will work
- One problem remains is what if user enters value like
'dh\''ruv'