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我正在尝试从现有数据库中检索数据。我最近从 Expo 管理切换到裸工作流，尝试使用 TypeORM 测试 react-native-sqlite-storage。但是，TypeORM 原始查询一直返回一个空数组，我不知道为什么。

这是我的代码，它基于此示例https://dev.to/jgabriel1/expo-sqlite-typeorm-4mn8

DictionaryScreen.js

function DictionaryScreen(props) {
    const { ejRepository } = useDatabaseConnection();

    const handleinputWord = async () => {
        console.log(props.inputWord);  //=>this console.logs the text from the input below 
        try {
            const results = await ejRepository.getWordandMean(props.inputWord);
            
            console.log(results); //=> Here I expect an array of the query result but it only returns []

        } catch (error) {
            console.log(error)
        }
    }

    return(
                <View style={styles.searchContainer}>
                    <MaterialCommunityIcons name="text-search" color="white" size={30}/>
                    <TextInput
                        style={styles.input}
                        onChangeText={props.updateTextInput}
                        onSubmitEditing={handleinputWord}
                        value={props.inputWord}
                        placeholder='Look up the word (Type exactly)'
                        keyboardType="default"
                    /> 
                <StatusBar style='light' />
                </View>
           )
}

const mapStateToProps = state => {
    return { 
        inputWord: state.inputWord
    }
};
    
const mapDispatchToProps = {updateTextInput};
    
    
export default connect(mapStateToProps, mapDispatchToProps) (DictionaryScreen);

存储库.ts

export class EJRepository {
    private ormRepository: Repository<EJModel>;

    constructor(connection: Connection) {
      this.ormRepository = connection.getRepository(EJModel);
    }

    public async getWordandMean(props: any): Promise<EJModel> {
      console.log(props);  //=> this returns the same text from DictionaryScreen

      const results = await this.ormRepository.query(
        `SELECT * FROM ejmodel WHERE word LIKE '%${props}%';`, [props]);
 
      return results;
    }
}

连接.tsx

interface DatabaseConnectionContextData {
    ejRepository: EJRepository;
}
  
const DatabaseConnectionContext = createContext<DatabaseConnectionContextData>(
    {} as DatabaseConnectionContextData,
  );
  
export const DatabaseConnectionProvider: React.FC = ({ children }) => {
　　　const [connection, setConnection] = useState<Connection | null>(null);
  
　　　const connect = useCallback(async () => {
      　const createdConnection = await createConnection({
        　　type: 'react-native',
        　　name: "ejdict.v1.0",
        　　database: '***.db',
        　　entities: [EJModel],
           location: 'default',
       　　 migrations: [ejdict1621603544180],
        　　migrationsRun: true,
        　　synchronize: false,
           logging: true,
        　　extra: {createFromLocation: '/Users/***/***/ios/***/www/***.db' }
      　});
  
      　setConnection(createdConnection);
    　}, []);
  
    useEffect(() => {
      if (!connection) {
        connect();
      }
    }, [connect, connection]);
  
    if (!connection) {
      return <ActivityIndicator />;
    }
  
return (
  　<DatabaseConnectionContext.Provider
      value={{
        ejRepository: new EJRepository(connection),
      }}
    >
      {children}
    </DatabaseConnectionContext.Provider>
  );
};

export function useDatabaseConnection() {
  const context = useContext(DatabaseConnectionContext);

  return context;
}

EJModel.ts

import {Entity, PrimaryColumn, Column} from "typeorm";

@Entity({name: "ejmodel"})
export class EJModel {

    @PrimaryColumn({type: 'integer'})
    item_id: number;

    @Column({type: 'text'})
    word: string;

    @Column({type: 'text'})
    mean: string;

    @Column({type: 'integer'})
    level: number;
}

PS：在 React Native 项目中加载现有数据库是一种不寻常的尝试吗？工作示例几乎不存在。我曾经让它在 Expo 上工作，但我意识到我需要迁移功能，并试图用 TypeORM 做同样的事情，浪费大量时间......

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