It's the most popular Python framework and is widely trusted. It is used to build systems like Instagram.

It's relatively tightly coupled with relational databases (like MySQL or PostgreSQL), so, having a NoSQL database (like Couchbase, MongoDB, Cassandra, etc) as the main store engine is not very easy.

 */
public class BadWordService {

    private static final String DELETE_PREFIX = "--";

    private static final Logger logger = LogManager.getLogger(BadWordService.class);

    /** Database behavior for bad word operations. */
    @Resource
    protected BadWordBhv badWordBhv;

    /** Search engine client for index operations. */
    @Resource
    protected SearchEngineClient searchEngineClient;

package logger_test

import (
	"database/sql/driver"
	"encoding/json"
	"fmt"
	"regexp"
	"strings"
	"testing"

	"github.com/jinzhu/now"
	"gorm.io/gorm/logger"
)

type JSON json.RawMessage

func (j JSON) Value() (driver.Value, error) {
	if len(j) == 0 {
		return nil, nil
	}
	return json.RawMessage(j).MarshalJSON()
}

type ExampleStruct struct {
	Name string
	Val  string
}

package logger

import (
	"database/sql/driver"
	"fmt"
	"reflect"
	"regexp"
	"strconv"
	"strings"
	"time"
	"unicode"

	"gorm.io/gorm/utils"
)

const (
	tmFmtWithMS = "2006-01-02 15:04:05.999"
	tmFmtZero   = "0000-00-00 00:00:00"
	nullStr     = "NULL"
)

func isPrintable(s string) bool {
	for _, r := range s {
		if !unicode.IsPrint(r) {
			return false
		}
	}
	return true
}

 * limitations under the License.
 */
package okhttp3.internal.publicsuffix

import java.net.IDN
import okhttp3.internal.and
import okio.ByteString
import okio.ByteString.Companion.encodeUtf8

/**
 * A database of public suffixes provided by [publicsuffix.org][publicsuffix_org].
 *
 * [publicsuffix_org]: https://publicsuffix.org/
 */
class PublicSuffixDatabase internal constructor(
  private val publicSuffixList: PublicSuffixList,

package clause_test

import (
	"database/sql"
	"fmt"
	"reflect"
	"sync"
	"testing"

	"gorm.io/gorm"
	"gorm.io/gorm/clause"
	"gorm.io/gorm/schema"
	"gorm.io/gorm/utils/tests"
)

func TestExpr(t *testing.T) {
	results := []struct {
		SQL    string
		Result string
		Vars   []interface{}
	}{{
		SQL:    "create table ? (? ?, ? ?)",

                .selectByPK(id)
                .filter(e -> Boolean.TRUE.equals(e.getAvailable()))
                .isPresent();
    }

    /**
     * Stores a job log entry in the database.
     *
     * @param jobLog the job log entry to store
     */
    public void store(final JobLog jobLog) {
        ComponentUtil.getComponent(JobLogBhv.class).insertOrUpdate(jobLog, op -> {

package tests_test

import (
	"database/sql/driver"
	"encoding/json"
	"errors"
	"reflect"
	"testing"
	"time"

	"gorm.io/gorm"
	. "gorm.io/gorm/utils/tests"
)

func TestEmbeddedStruct(t *testing.T) {
	type ReadOnly struct {
		ReadOnly *bool
	}

	type BasePost struct {
		Id    int64
		Title string
		URL   string
		ReadOnly
	}

	type Author struct {
		ID    string
		Name  string

This is especially the case for user models, because:

* The **input model** needs to be able to have a password.
* The **output model** should not have a password.
* The **database model** would probably need to have a hashed password.

/// danger

Never store user's plaintext passwords. Always store a "secure hash" that you can then verify.

You will see examples of this in the next chapters, about relational and NoSQL databases, security, etc.

## **FastAPI** compatibility { #fastapi-compatibility }

The simplicity of the dependency injection system makes **FastAPI** compatible with:

* all the relational databases
* NoSQL databases
* external packages
* external APIs
* authentication and authorization systems