sqlite3x 
Overview
sqlite3x is a fork of the sqlite3 codebase that provides 100% compatibility with sqlite3. Data read or modified in either sqlite3 ot sqlite3x is always compatible with the other one.
sqlite3x is kept up to date with the latest sqlite3 codebase and contains modifications that sit on top of the engine, such as new functions.
The only compatibility issues will be that if you use sqlite3x functions, they will obviously not be available for use in queries on a vanilla sqlite3 command line or linked library.
Features
Added Functions
On top of the sqlite3 built-in functions, sqlite3x adds:
acos(X)
acos(X) returns the arc-cosine of X. If X is NULL, then the result will be
NULL.
If X not numeric then it will be treated internally as 0.0. This will
produce a result of 1.5707963267949.
asin(X)
asin(X) returns the arc-sine of X. If X is NULL, then the result will be
NULL.
If X not numeric then it will be treated internally as 0.0. This will
produce a result of 0.0.
atan(X)
atan(X) returns the arc-tangent of X. If X is NULL, then the result will
be NULL.
If X not numeric then it will be treated internally as 0.0. This will
produce a result of 0.0.
atan2(Y,X)
atan2(Y,X) returns arc-tangent with Y and X. NULL is returned if either of
the inputs are NULL.
You should be careful that inputs are valid and sensible. atan2(Y,X) does not provide any protection for values that are invalid (not valid numbers).
ceil(X)
ceil(X) rounds X upward, returning the smallest integral value that is not
less than X. If X is NULL, then the result will be NULL, otherwise the
result will always be a floating-point value.
If X not numeric then it will be treated internally as 0.0. This will
produce a result of 0.0.
cos(X)
cos(X) returns the cosine of X (X is expressed in radians). If X is
NULL, then the result will be NULL.
If X not numeric then it will be treated internally as 0.0. This will
produce a result of 1.0.
cosh(X)
cosh(X) returns the hyperbolic cosine of X. If X is NULL, then the result
will be NULL.
If X not numeric then it will be treated internally as 0.0. This will
produce a result of 0.0.
e()
e() returns the value of e, which is approximately 2.71828.
exp(X)
exp(X) returns e to the power of X. If X is NULL, then the result will
be NULL.
If X not numeric then it will be treated internally as 0.0. This will
produce a result of 1.0.
exp(X) does not provide any protection for result values that are too small or large (overflow) will have unexpected behavior depending on your system.
floor(X)
floor(X) rounds X downward, returning the largest integral value that is not
greater than X. If X is NULL, then the result will be NULL, otherwise
the result will always be a floating-point value.
If X not numeric then it will be treated internally as 0.0. This will
produce a result of 0.0.
log(X)
log(X) returns natural logarithm (base e) of X. If X is NULL, then the
result will be NULL.
If X not numeric then it will be treated internally as 0.0. This will
produce a result of -Inf.
log10(X)
log10(X) returns common logarithm (base 10) of X. If X is NULL, then the
result will be NULL.
If X not numeric then it will be treated internally as 0.0. This will
produce a result of -Inf.
pi()
pi() returns the value of pi, which is approximately 3.14159.
pow(X,Y)
pow(X,Y) returns X to the power of Y. The result is always a floating-point
value. NULL is returned if either of the inputs are NULL.
You should be careful that inputs are valid and sensible. pow(X,Y) does not provide any protection for values that are invalid (not valid numbers). Result values that are too small or large (overflow) will have unexpected behavior depending on your system.
sin(X)
sin(X) returns the sine of X (X is expressed in radians). If X is NULL,
then the result will be NULL.
If X not numeric then it will be treated internally as 0.0. This will
produce a result of 0.0.
sinh(X)
sinh(X) returns the hyperbolic sine of X. If X is NULL, then the result
will be NULL.
If X not numeric then it will be treated internally as 0.0. This will
produce a result of 0.0.
sqrt(X)
sqrt(X) returns the square root of X. If X is NULL, then the result will
be NULL.
If X not numeric then it will be treated internally as 0.0. This will
produce a result of 0.0.
tan(X)
tan(X) returns the tangent of X (X is expressed in radians). If X is
NULL, then the result will be NULL.
If X not numeric then it will be treated internally as 0.0. This will
produce a result of 0.0.
tanh(X)
tanh(X) returns the hyperbolic tangent of X. If X is NULL, then the result
will be NULL.
If X not numeric then it will be treated internally as 0.0. This will
produce a result of 0.0.
Building From Source
Since sqlite3x inherits all of the source code from sqlite3, it also inherits the build and test system that has been designed to work with many operating systems.
Even though the process is the same (all of the documentation on sqlite.org can be used), keep in mind that extra targets have been added with an "x" on the end. This is so source and binaries that are distributed will not get confused or replace any vanilla version of sqlite3.
You can clone this repository, or download a zip of the latest stable code.
Binary Client
The binary client is the interactive shell you can use in your terminal to operate sqlite3 databases. It can be built and updated with:
./configure
make sqlite3x # For macOS and linux.
make sqlite3x.exe # For windows.
# You may want to move the binary into $PATH so it can be used anywhere.
Amalgamation Source
The amalgamation source is the most recommended way to integrate with your existing source/application. Use make to produce two files that can be included in your project:
./configure
make sqlite3x.c sqlite3x.h
Testing
Running the full test suite is recommended before integrating sqlite3x into your application.
The full test suite (including TCL tests for both core and sqlite3x) can be run with:
make test
It can take some time to run the full suite. If you want to run a specific test you can use:
make testfixture && ./testfixture test/main.test
Updating SQLite3 Core
As new versions of sqlite3 are released, the core source code can be updated with:
fossil clone https://www.sqlite.org/src sqlite.fossil
fossil open sqlite.fossil
fossil update release