Make INNER JOIN with more than one table

Question

I want to relate Inner Join in the Employee table with Address, And department and function but only that the function table is foreign key in the department table.

INNER JOIN no C#

SqlDataAdapter QIG4A = new SqlDataAdapter();
                string sql4A = "SELECT DP.ID_DEPARTAMENTO, DP.NOME_DEP, FUNCAO.NOME_FUNCAO, FUNCAO.SALARIO FROM DEPARTAMENTO AS DP INNER JOIN FUNCAO ON DP.ID_FUNCAO = FUNCAO.ID_FUNCAO;";
                DataTable tb4A = new DataTable();
                QIG4A = new SqlDataAdapter(sql4A, Q1.SMS());
                QIG4A.Fill(tb4A);
                comboBoxEx3.DataSource = tb4A;
                comboBoxEx3.DisplayMember = "NOME_DEP";
                comboBoxEx4.DataSource = tb4A;
                comboBoxEx4.DisplayMember = "NOME_FUNCAO";
                comboBoxEx18.DataSource = tb4A;
                comboBoxEx18.DisplayMember = "SALARIO";
                comboBoxEx19.DataSource = tb4A;
                comboBoxEx19.DisplayMember = "ID_DEPARTAMENTO";

the tables

CREATE TABLE FUNCIONARIO
(
    ID_FUNCIONARIO INT IDENTITY(1,1),
    NOME_FUNCIONARIO VARCHAR(100) NOT NULL,
    NOME_PAI VARCHAR(100) NOT NULL,
    NOME_MAE VARCHAR(100)NOT NULL,
    N_BI VARCHAR(50)UNIQUE NOT NULL,
    DATA_NASC VARCHAR(100) NOT NULL,
    GENERO VARCHAR(100) NOT NULL,
    ESTA_CIVIL VARCHAR(100)NOT NULL,
    FOTO VARCHAR (100) NOT NULL,
    ID_DEPARTAMENTO INT,
    ID_MUNICIPIO INT,
    DATA_HORA VARCHAR (100)NOT NULL,
    USUARIO VARCHAR (100)NOT NULL,
    CONSTRAINT PK_FUNC PRIMARY KEY (ID_FUNCIONARIO),

    CONSTRAINT PK_FUNC_MUNI FOREIGN KEY (ID_MUNICIPIO)
    REFERENCES FUNCAO (ID_FUNCAO),

    CONSTRAINT PK_FUNC_DEP FOREIGN KEY (ID_DEPARTAMENTO)
    REFERENCES DEPARTAMENTO (ID_DEPARTAMENTO)

)

CREATE TABLE ENDERECO
(
    ID_ENDERECO INT IDENTITY(1,1),
    ID_PROVINCIA INT,
    ID_MUNICIPO INT,
    RUA VARCHAR (100),
    BAIRRO VARCHAR (100),
    N_CASA VARCHAR(100),
    CONSTRAINT PK_ENDERECO PRIMARY KEY (ID_ENDERECO),
    CONSTRAINT PK_END_PROV FOREIGN KEY (ID_PROVINCIA)
    REFERENCES PROVINCIA(ID_PROVINCIA),
    CONSTRAINT PK_END_MUN FOREIGN KEY (ID_MUNICIPO)
    REFERENCES MUNICIPIO(ID_MUNICIPO)
)

CREATE TABLE PROVINCIA
(
    ID_PROVINCIA int identity(1,1),
    NOME_PROVINCIA VARCHAR(100),
    CONSTRAINT PK_PROVINCIA PRIMARY KEY(ID_PROVINCIA)
)

CREATE TABLE MUNICIPIO
(
    ID_MUNICIPO INT IDENTITY(1,1),
    NOME_MUNICIPIO VARCHAR (100),
    ID_PROVINCIA INT,
    CONSTRAINT PK_MUNICIPO PRIMARY KEY (ID_MUNICIPO),
    CONSTRAINT PK_MUN_PROV FOREIGN KEY(ID_PROVINCIA)
     REFERENCES PROVINCIA(ID_PROVINCIA)
)

CREATE TABLE DEPARTAMENTO
(
    ID_DEPARTAMENTO INT IDENTITY(1,1),
    NOME_DEP VARCHAR(100)NOT NULL,
    ID_FUNCAO INT ,
    CONSTRAINT PK_DEP PRIMARY KEY (ID_DEPARTAMENTO),
    CONSTRAINT PK_DEP_FUNCAO FOREIGN KEY (ID_FUNCAO)
    REFERENCES FUNCAO (ID_FUNCAO)
)
USE PRESENCA1
CREATE TABLE FUNCAO
(
    ID_FUNCAO INT IDENTITY(1,1),
    NOME_FUNCAO VARCHAR(100)NOT NULL,
    SALARIO VARCHAR(100)NOT NULL,
    DATA VARCHAR(100) NOT NULL,
    CONSTRAINT PK_FUNCAO PRIMARY KEY (ID_FUNCAO)
)

And also in datagridviews are appearing Ids instead of names

Answer 1

Mario, see that, vc created a relationship between the Department tables and function, this will allow the joins, when necessary. For the employee and department tables, you will need to create a table that will store the relationships between these tables, like the Function and Iddepto, this will solve whenever you need to relate an employee to a department and vice versa. This applies to other tables in their structure, which do not have a relationship.