mirror of
https://github.com/rbock/sqlpp11.git
synced 2024-12-26 07:53:21 +08:00
283 lines
11 KiB
Markdown
283 lines
11 KiB
Markdown
sqlpp11
|
||
=======
|
||
A type safe embedded domain specific language for SQL queries and results in C++.
|
||
|
||
```diff
|
||
!If you are a tenured user of sqlpp11, please note that
|
||
! - with 0.61 the connector libraries for mysql/sqlite/postgresql got merged into the main repo.
|
||
! - master has been renamed to main and is now the default branch
|
||
```
|
||
|
||
Documentation is found in [docs](docs/Home.md).
|
||
|
||
So what is this about?
|
||
----------------------
|
||
SQL and C++ are both strongly typed languages. Still, most C/C++ interfaces to SQL are based on constructing queries as strings and on interpreting arrays or maps of strings as results.
|
||
|
||
sqlpp11 is a templated library representing an embedded domain specific language (EDSL) that allows you to
|
||
|
||
* define types representing tables and columns,
|
||
* construct type safe queries checked at compile time for syntax errors, type errors, name errors and even some semantic errors,
|
||
* interpret results by iterating over query-specific structs with appropriately named and typed members.
|
||
|
||
This results in several benefits, e.g.
|
||
|
||
* the library user operates comfortably on structs and functions,
|
||
* the compiler reports many kinds of errors long before the code enters unit testing or production,
|
||
* the library hides the gory details of string construction for queries and interpreting results returned by select calls.
|
||
|
||
The library supports both static and dynamic queries. The former offers greater benefit in terms of type and consistency checking. The latter makes it easier to construct queries in flight.
|
||
|
||
sqlpp11’s core is vendor-neutral.
|
||
Specific traits of databases (e.g. unsupported or non-standard features) are handled by connector libraries.
|
||
Connector libraries can inform the developer of missing features at compile time.
|
||
They also interpret expressions specifically where needed.
|
||
For example, the connector could use the operator|| or the concat method for string concatenation without the developer being required to change the statement.
|
||
|
||
Connectors for MariaDB, MySQL, PostgreSQL, sqlite3, sqlcipher are included in this repository.
|
||
|
||
The library is already used in production but it is certainly not complete yet. Feature requests, bug reports, contributions to code or documentation are most welcome.
|
||
|
||
Examples:
|
||
---------
|
||
For the examples, lets assume you have a table class representing something like
|
||
|
||
```SQL
|
||
CREATE TABLE foo (
|
||
id bigint,
|
||
name varchar(50),
|
||
hasFun bool
|
||
);
|
||
```
|
||
|
||
And we assume to have a database connection object:
|
||
|
||
```C++
|
||
TabFoo foo;
|
||
Db db(/* some arguments*/);
|
||
|
||
// selecting zero or more results, iterating over the results
|
||
for (const auto& row : db(select(foo.name, foo.hasFun).from(foo).where(foo.id > 17 and foo.name.like("%bar%"))))
|
||
{
|
||
if (row.name.is_null())
|
||
std::cerr << "name is null, will convert to empty string" << std::endl;
|
||
std::string name = row.name; // string-like fields are implicitly convertible to string
|
||
bool hasFun = row.hasFun; // bool fields are implicitly convertible to bool
|
||
}
|
||
|
||
// selecting ALL columns of a table
|
||
for (const auto& row : db(select(all_of(foo)).from(foo).where(foo.hasFun or foo.name == "joker")))
|
||
{
|
||
int64_t id = row.id; // numeric fields are implicitly convertible to numeric c++ types
|
||
}
|
||
|
||
// selecting zero or one row, showing off with an alias:
|
||
SQLPP_ALIAS_PROVIDER(cheese);
|
||
if (const auto& row = db(select(foo.name.as(cheese)).from(foo).where(foo.id == 17)))
|
||
{
|
||
std::cerr << "found: " << row.cheese << std::endl;
|
||
}
|
||
|
||
// selecting a single row with a single result:
|
||
return db(select(count(foo.id)).from(foo).unconditionally()).front().count;
|
||
|
||
Of course there are joins and subqueries, more functions, order_by, group_by etc.
|
||
These will be documented soon.
|
||
|
||
// A sample insert
|
||
db(insert_into(foo).set(foo.id = 17, foo.name = "bar", foo.hasFun = true));
|
||
|
||
// A sample update
|
||
db(update(foo).set(foo.hasFun = not foo.hasFun).where(foo.name != "nobody"));
|
||
|
||
// A sample delete
|
||
db(remove_from(foo).where(not foo.hasFun));
|
||
```
|
||
|
||
License:
|
||
-------------
|
||
sqlpp11 is distributed under the [BSD 2-Clause License](https://github.com/rbock/sqlpp11/blob/master/LICENSE).
|
||
|
||
Status:
|
||
-------
|
||
Branch / Compiler | clang, gcc | MSVC | Test Coverage
|
||
------------------|-------------|--------|---------------
|
||
master | [](https://travis-ci.com/rbock/sqlpp11?branch=master) | [](https://ci.appveyor.com/project/rbock/sqlpp11/branch/master) | [](https://coveralls.io/r/rbock/sqlpp11?branch=master)
|
||
develop | [](https://travis-ci.com/rbock/sqlpp11?branch=develop) | [](https://ci.appveyor.com/project/rbock/sqlpp11/branch/develop) | [](https://coveralls.io/r/rbock/sqlpp11?branch=develop)
|
||
|
||
Additional information available:
|
||
---------------------------------
|
||
Past talks about sqlpp11 and some coding concepts used within the library:
|
||
|
||
* [CppCast:](http://cppcast.com)
|
||
* 2015-05-07: http://cppcast.com/2015/05/roland-bock/
|
||
* [CppCon:](http://cppcon.org)
|
||
* 2015-09-24: [Pruning Error Messages From Your C++ Template Code](https://www.youtube.com/watch?v=2ISqFW9fRws), with examples from sqlpp11
|
||
* 2014-09-11: [sqlpp11, An SQL Library Worthy Of Modern C++](https://www.youtube.com/watch?v=cJPAjhBm-HQ)
|
||
* [Meeting C++:](http://meetingcpp.com)
|
||
* 2014-12-05: [sqlpp11, An EDSL For Type-Safe SQL In C++11](https://www.youtube.com/watch?v=9Hjfg9IfzhU)
|
||
* [MUC++:](http://www.meetup.com/MUCplusplus/)
|
||
* 2014-02-27: [Selected C++11 Template Toffees From sqlpp11, Part1](https://www.youtube.com/watch?v=hXnGFYNbmXg), [Part2](https://www.youtube.com/watch?v=WPCV6dvxZ_U), [Part 3](https://www.youtube.com/watch?v=eB7hd_KjTig), [Part 4](https://www.youtube.com/watch?v=NBfqzcN0_EQ)
|
||
|
||
|
||
Requirements:
|
||
-------------
|
||
__Compiler:__
|
||
sqlpp11 makes heavy use of C++11 and requires a recent compiler and STL. The following compilers are known to compile the test programs:
|
||
|
||
* clang-3.4+ on Ubuntu-12.4
|
||
* g++-4.8+ on Ubuntu-12.4
|
||
* g++-4.8+ on cygwin 64bit
|
||
* g++-4.9+ on Debian Unstable
|
||
* Xcode-7 on OS X
|
||
* MSVC 2015 Update 1 on Windows Server 2012
|
||
|
||
__Database Connector:__
|
||
sqlpp11 requires a certain api in order to connect with the database, see database/api.h.
|
||
|
||
This repository includes the following connectors:
|
||
|
||
* MySQL
|
||
* MariaDB
|
||
* SQLite3
|
||
* SQLCipher
|
||
* PostgreSQL
|
||
|
||
Other connectors can be found here:
|
||
|
||
* ODBC: https://github.com/Erroneous1/sqlpp11-connector-odbc (experimental)
|
||
|
||
__Date Library:__
|
||
sqlpp11 requires [Howard Hinnant’s date library](https://github.com/HowardHinnant/date) for `date` and `date_time` data types. By default, sqlpp11 uses FetchContent to pull the library automatically in the project. If you want to use an already installed version of the library with `find_package`, set `USE_SYSTEM_DATE` option to `ON`.
|
||
|
||
Build and Install
|
||
-----------------
|
||
|
||
**Note**: Depending on how you use the lib, you might not need to install it (see Basic Usage)
|
||
|
||
__Build from Source:__
|
||
|
||
Download and unpack the latest release from https://github.com/rbock/sqlpp11/releases or clone the repository. Inside the directory run the following commands:
|
||
|
||
```bash
|
||
cmake -B build
|
||
cmake --build build --target install
|
||
```
|
||
|
||
The last step will build the library and install it system wide, therefore it might need admins rights.
|
||
|
||
By default only the core library will be installed. To also install connectors set the appropriate variable to `ON`:
|
||
|
||
* `BUILD_MYSQL_CONNECTOR`
|
||
* `BUILD_MARIADB_CONNECTOR`
|
||
* `BUILD_POSTGRESQL_CONNECTOR`
|
||
* `BUILD_SQLITE3_CONNECTOR`
|
||
* `BUILD_SQLCIPHER_CONNECTOR`
|
||
|
||
The library will check if all required dependencies are installed on the system. If connectors should be installed even if the dependencies are not yet available on the system, set `DEPENDENCY_CHECK` to `OFF`.
|
||
|
||
Example: Install the core library, sqlite3 connector and postgresql connector. Don’t check if the dependencies such as Sqlite3 are installed and don’t build any tests:
|
||
|
||
```bash
|
||
cmake -B build -DBUILD_POSTGRESQL_CONNECTOR=ON -DBUILD_SQLITE3_CONNECTOR=ON -DDEPENDENCY_CHECK=OFF -DBUILD_TESTING=OFF
|
||
cmake --build build --target install
|
||
```
|
||
|
||
__Install via Homebrew (MacOS):__
|
||
|
||
```bash
|
||
brew install marvin182/zapfhahn/sqlpp11
|
||
```
|
||
|
||
Some connectors can be installed with the formula. See `brew info marvin182/zapfhahn/sqlpp11` for available options.
|
||
|
||
__Build via vcpkg:__
|
||
|
||
You can download and install sqlpp11 using the [vcpkg](https://github.com/Microsoft/vcpkg) dependency manager:
|
||
|
||
```bash
|
||
git clone https://github.com/Microsoft/vcpkg.git
|
||
cd vcpkg
|
||
./bootstrap-vcpkg.sh
|
||
./vcpkg integrate install
|
||
./vcpkg install 'sqlpp11[mysql]' # or other database feature
|
||
```
|
||
|
||
The sqlpp11 port in vcpkg is kept up to date by Microsoft team members and community contributors. If the version is out of date, please [create an issue or pull request](https://github.com/Microsoft/vcpkg) on the vcpkg repository.
|
||
|
||
Basic usage:
|
||
-------------
|
||
__Use with cmake__:
|
||
The library officially supports two ways how it can be used with cmake.
|
||
You can find examples for both methods in the examples folder.
|
||
|
||
1. FetchContent (Recommended, no installation required)
|
||
1. FindPackage (installation required, see above)
|
||
|
||
Both methods will provide the `sqlpp11::sqlpp11` target as well as targets for each connector:
|
||
|
||
* sqlpp11::mysql
|
||
* sqlpp11::mariadb
|
||
* sqlpp11::sqlite3
|
||
* sqlpp11::sqlcipher
|
||
* sqlpp11::postgresql
|
||
|
||
These targets will make sure all required dependencies are available and correctly linked and include directories are set correctly.
|
||
|
||
__Create DDL files__:
|
||
```
|
||
mysql: 'show create table MyDatabase.MyTable' #or
|
||
mysqldump --no-data MyDatabase > MyDatabase.sql
|
||
|
||
```
|
||
Create headers for them with provided Python script:
|
||
```
|
||
%sqlpp11_dir%/scripts/ddl2cpp ~/temp/MyTable.ddl ~/temp/MyTable %DatabaseNamespaceForExample%
|
||
```
|
||
|
||
In case you’re getting notes about unsupported column type consider:
|
||
- Take a look at the other datatypes in sqlpp11/data_types. They are not hard to implement.
|
||
- Use the `--datatype-file` command line argument as described below.
|
||
|
||
Include generated header (MyTable.h), that’s all.
|
||
|
||
If you prefer Ruby over Python, you might want to take a look at https://github.com/douyw/sqlpp11gen
|
||
|
||
Unsupported column types:
|
||
-------------
|
||
__Map unsupported column types to supported column types with a csv file__:
|
||
|
||
One can use the `--datatype-file` command line argument for the ddl2cpp script to map unsupported column types to supported column types.
|
||
|
||
The format of the csv file is:
|
||
```
|
||
<dataType>, <col_type1>, <col_type2>
|
||
<dataType>, <col_type3>
|
||
```
|
||
|
||
Where `<dataType>` is one or more of the following internal types:
|
||
|
||
- `Boolean`
|
||
- `Integer`
|
||
- `Serial`
|
||
- `FloatingPoint`
|
||
- `Text`
|
||
- `Blob`
|
||
- `Date`
|
||
- `DateTime`
|
||
- `Time`
|
||
|
||
Example:
|
||
|
||
```
|
||
Boolean, one_or_zero
|
||
Text, url, uuid
|
||
```
|
||
|
||
Contact:
|
||
--------
|
||
* Issues at https://github.com/rbock/sqlpp11/issues
|
||
* email at rbock at eudoxos dot de
|
||
* [](https://gitter.im/sqlpp11/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
|
||
|