{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[21:22] hl[21:22] *}

### Create a Session Dependency { #create-a-session-dependency }

A **`Session`** is what stores the **objects in memory** and keeps track of any changes needed in the data, then it **uses the `engine`** to communicate with the database.

     *
     * <p><b>Note:</b> in general, code should assume that the string form returned by {@code
     * ToStringHelper} for a given object may change. In particular, the list of types which are
     * checked for emptiness is subject to change. We currently check {@code CharSequence}s, {@code
     * Collection}s, {@code Map}s, optionals (including Guava's), and arrays.
     *
     * @since 33.4.0
     */

## 关于版本

遵循语义版本控制约定，任何低于`1.0.0`的版本都可能会添加 breaking changes。

FastAPI 还遵循这样的约定：任何`PATCH`版本更改都是为了bug修复和non-breaking changes。

/// tip

"PATCH"是最后一个数字，例如，在`0.2.3`中，PATCH版本是`3`。

///

因此，你应该能够固定到如下版本：

```txt
fastapi>=0.45.0,<0.46.0
```

"MINOR"版本中会添加breaking changes和新功能。

/// tip

"MINOR"是中间的数字，例如，在`0.2.3`中，MINOR版本是`2`。

///

## 升级FastAPI版本

     * to quickly open the changes file.  By then we can also regex that path out of the description
     * in order to create a changes {@link File} for further use in this class.
     *
     * @param data the report data containing a description to parse
     * @return accepted api changes reported upon, as a file
     */

                "Method com.example.Source.plus(int,java.util.List): Breaking Kotlin modifier change.",
                "Method com.example.SourceKt.invoke(java.lang.String,int): Breaking Kotlin modifier change.",
                "Method com.example.SourceKt.invoke(long,int): Breaking Kotlin modifier change.",

  "scenario" : "org.gradle.performance.regression.android.AndroidIncrementalExecutionPerformanceTest.abi change",
  "durations" : [ {
    "testProject" : "nowInAndroidBuild",
    "linux" : 399,
    "windows" : 454,
    "macOs" : 331
  } ]
}, {
  "scenario" : "org.gradle.performance.regression.android.AndroidIncrementalExecutionPerformanceTest.abi change with configuration caching",
  "durations" : [ {
    "testProject" : "nowInAndroidBuild",

    }

    def "can clean existing API changes"() {
        given:
        jsonFile << existingAcceptedApiChanges()

        when:
        jsonFileManager.emptyAcceptedApiChanges(jsonFile)

        then:
        jsonFile.text == nonExistentAcceptedApiChanges()
    }

    def "can clean non-existing API changes"() {
        given:
        jsonFile << nonExistentAcceptedApiChanges()

 * deep support for asynchronous operations</a>. But if you want to migrate to Caffeine with minimal
 * code changes, you can use <a
 * href="https://www.javadoc.io/doc/com.github.ben-manes.caffeine/guava/latest/com.github.benmanes.caffeine.guava/com/github/benmanes/caffeine/guava/CaffeinatedGuava.html">its

## Expected Behavior
<!--- If you're describing a bug, tell us what should happen -->
<!--- If you're suggesting a change/improvement, tell us how it should work -->

## Current Behavior
<!--- If describing a bug, tell us what happens instead of the expected behavior -->
<!--- If suggesting a change/improvement, explain the difference from current behavior -->

## Possible Solution

    "groups" : [ {
      "testProject" : "nowInAndroidBuild",
      "coverage" : {
        "per_commit" : [ "linux", "windows", "macOs" ]
      }
    } ]
  }, {
    "testId" : "org.gradle.performance.regression.android.AndroidIncrementalExecutionPerformanceTest.abi change with configuration caching",
    "groups" : [ {