Added explanation of SQLITE_DQS=0 compile flag

README.md

@@ -18,3 +18,50 @@ process. This is done by handling all commands from erlang within a
 lightweight thread. The erlang scheduler will get control back when
 the command has been added to the command-queue of the thread.
 
+SQLite Compile Options
+----------------------
+
+Esqlite contains an embedded version of sqlite3. Currently version
+`3.37.2` is embedded in the repositoy. It is also possible to use 
+sqlite provided by the system by using the `ESQLITE_USE_SYSTEM` 
+environment flag. 
+
+When sqlite is compiled, the following compile flags are used. These
+flags are recommended by sqlite.
+
+```
+SQLITE_DQS=0 SQLITE_THREADSAFE=1 SQLITE_DEFAULT_MEMSTATUS=0
+SQLITE_DEFAULT_WAL_SYNCHRONOUS=1 SQLITE_LIKE_DOESNT_MATCH_BLOBS
+SQLITE_MAX_EXPR_DEPTH=0 SQLITE_OMIT_DEPRECATED
+SQLITE_OMIT_PROGRESS_CALLBACK SQLITE_USE_ALLOCA
+SQLITE_OMIT_AUTOINIT SQLITE_USE_URI
+SQLITE_ENABLE_FTS3 SQLITE_ENABLE_FTS3_PARENTHESIS
+SQLITE_ENABLE_FTS4
+SQLITE_ENABLE_FTS5
+SQLITE_ENABLE_MATH_FUNCTIONS
+SQLITE_ENABLE_JSON1
+SQLITE_ENABLE_RTREE
+```
+
+The use of flag `SQLITE_DQS=0` is new in version `0.7`. It can lead
+to incompatibilities with respect to the use of single and double 
+qouted values. Historically sqlite didn't differentiate between double
+and single quoted values, but SQL does. In retrospect, the authors of 
+sqlite, think this was a mistake, and introduced this compile flag 
+to correct this mistake. It means that string literals **must** use 
+single quotes:
+
+```
+INSERT INTO table VALUES('abcd', 1234);
+```
+
+When double quotes are used the value is seen as object values in 
+SQL. So a query like:
+
+```
+INSERT INTO table VALUES("abcd", 1234);
+```
+
+Will not work, because it sees the value 'abcd' as a SQL object
+value, and not a string literal.
+