```Python hl_lines="3  6-8  11-12  23-24  27-28"
{!> ../../docs_src/sql_databases/sql_app/schemas.py!}
```

////

#### SQLAlchemy 风格和 Pydantic 风格

请注意，SQLAlchemy*模型*使用 `=`来定义属性，并将类型作为参数传递给`Column`，例如：

```Python
name = Column(String)
```

虽然 Pydantic*模型*使用`:` 声明类型，但新的类型注释语法/类型提示是：

```Python
name: str
```

请牢记这一点，这样您在使用`:`还是`=`时就不会感到困惑。

### 创建用于读取/返回的Pydantic*模型/模式*

			end := fset.Position(old.End())
			// Subtract 1 from the column if we are going to
			// append a close parenthesis. That will set the
			// correct column for the following characters.
			sub := 0
			if r.Name.Kind != "type" {
				sub = 1
			}
			if end.Column > sub {
				repl = fmt.Sprintf("%s /*line :%d:%d*/", repl, end.Line, end.Column-sub)
			}
			if r.Name.Kind != "type" {

	}
	var args []string
	// The C preprocessor treats
	//	#define A(x)
	// and
	//	#define A (x)
	// distinctly: the first is a macro with arguments, the second without.
	// Distinguish these cases using the column number, since we don't
	// see the space itself. Note that text/scanner reports the position at the
	// end of the token. It's where you are now, and you just read this token.
	if tok == '(' && in.Stack.Col() == prevCol+1 {

.card:not(:first-child) .card-footer {\n    border-bottom-left-radius: 0;\n  }\n}\n\n.card-columns .card {\n  margin-bottom: 0.75rem;\n}\n\n@media (min-width: 576px) {\n  .card-columns {\n    -webkit-column-count: 3;\n    -moz-column-count: 3;\n    column-count: 3;\n    -webkit-column-gap: 1.25rem;\n    -moz-column-gap: 1.25rem;\n    column-gap: 1.25rem;\n    orphans: 1;\n    widows: 1;\n  }\n  .card-columns .card {\n    display: inline-block;\n    width: 100%;\n  }\n}\n\n.accordion {\n  overflow-anchor:...

## Execution of dependencies with `yield`

The sequence of execution is more or less like this diagram. Time flows from top to bottom. And each column is one of the parts interacting or executing code.

```mermaid
sequenceDiagram

participant client as Client
participant handler as Exception handler
participant dep as Dep with yield

      synchronized (mutex) {
        return map(delegate().row(rowKey), mutex);
      }
    }

    @Override
    public Map<R, V> column(@ParametricNullness C columnKey) {
      synchronized (mutex) {
        return map(delegate().column(columnKey), mutex);
      }
    }

    @Override
    public Set<Cell<R, C, V>> cellSet() {
      synchronized (mutex) {

      synchronized (mutex) {
        return map(delegate().row(rowKey), mutex);
      }
    }

    @Override
    public Map<R, V> column(@ParametricNullness C columnKey) {
      synchronized (mutex) {
        return map(delegate().column(columnKey), mutex);
      }
    }

    @Override
    public Set<Cell<R, C, V>> cellSet() {
      synchronized (mutex) {

+'"></span></a></td>'+(this.showSeconds?'<td class="separator">&nbsp;</td><td><a href="#" data-action="incrementSecond"><span class="'+this.icons.up+'"></span></a></td>':"")+(this.showMeridian?'<td class="separator">&nbsp;</td><td class="meridian-column"><a href="#" data-action="toggleMeridian"><span class="'+this.icons.up+'"></span></a></td>':"")+"</tr><tr><td>"+b+'</td> <td class="separator">:</td><td>'+c+"</td> "+(this.showSeconds?'<td class="separator">:</td><td>'+d+"</td>":"")+(this.showMeridian?'<td...

      </fields>
    </class>
    <!-- /BuildProfile support -->
    <class locationTracker="locations">
      <name>InputLocation</name>
      <version>2.0.0+</version>
      <fields>
        <!-- line, column and source fields are auto-generated by Modello -->
      </fields>
      <codeSegments>
        <codeSegment>
          <version>2.0.0+</version>
          <code>

    @Override

		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrEvaluatorBindingDoesNotExist: {
		Code:           "ErrEvaluatorBindingDoesNotExist",
		Description:    "A column name or a path provided does not exist in the SQL expression",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMissingHeaders: {
		Code:           "MissingHeaders",