外键约束不正确 - java-mysql [英] Foreign key constraint is incorrectly formed - java-mysql

问题描述

什么是mysql问题？
我不知道错误是什么，因为我之前没有使用过外键

what is the mysql problem ?? I do not know what the error is since I had not used foreign keys before

String clientes = "CREATE TABLE clientes("+
                    "ID INTEGER NOT NULL AUTO_INCREMENT,"+
                    "CUENTA INTEGER,"+
                    "NOMBRE VARCHAR(255),"+
                    "EDAD INTEGER,"+
                    "ADICIONAL INTEGER,"+
                    "DOMICILIO VARCHAR(255),"+
                    "PRIMARY KEY(ID))";

        String cuenta = "CREATE TABLE cuenta("+
                "CUENTA INTEGER,"+
                "SALDOAFAVOR DOUBLE(14,2),"+
                "SALDOENCONTRA DOUBLE(14,2),"+
                "FECHACORTE DATE,"+
                "LIMITECREDITO DOUBLE(14,2),"+
                "FOREIGN KEY(CUENTA) REFERENCES clientes(CUENTA))";

推荐答案

正确的引用和定义将使用主键：

The correct reference and definition would use the primary key:

CREATE TABLE cuenta (
    CUENTA INTEGER AUTO_INCREMENT PRIMARY KEY,
    CLIENTE_ID INT,
    SALDOAFAVOR NUMERIC(14, 2),
    SALDOENCONTRA NUMERIC(14, 2),
    FECHACORTE DATE,
    LIMITECREDITO NUMERIC(14,2),
    FOREIGN KEY(CLIENT_ID) REFERENCES clientes(ID)
);

注意：

• CUENTA 好像应该是这个表的主键。


• 外键引用应该使用id 客户。


• 您不需要 CUENTA >客户。


• DOUBLE（14,2）不是正确的数据类型。你想要 DECIMAL（14,2） / NUMERIC（14,2）。

• CUENTA seems like it should be the primary key of this table.
• The foreign key reference should use the id on CLIENTES.
• You don't need CUENTA on CLIENTES.
• DOUBLE(14, 2) is not the right data type. You want DECIMAL(14, 2)/NUMERIC(14, 2).

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