Dominando a Cláusula IF no MySQL: Um Guia Prático
Aprendendo a Utilizar Condições para Manipulação de Dados em Consultas MySQL
Lógica
A cláusula IF no MySQL funciona de forma semelhante a como o IF funciona em outras linguagens de programação. Ele permite que você crie uma condição e execute diferentes ações dependendo se a condição for verdadeira ou falsa. A sintaxe básica do IF é: IF (condição, valor_se_verdadeiro, valor_se_falso). Nesta consulta, estamos usando a cláusula IF para verificar se o "credito" é maior que 500. Se for, a cláusula IF retorna 'Bom', caso contrário, retorna 'Ruim'. O resultado desta expressão é então exibido em uma nova coluna chamada "status_credito". A cláusula IF é extremamente útil em situações onde você precisa categorizar ou fazer uma escolha entre dois valores com base em uma condição. A flexibilidade que ela oferece pode tornar suas consultas mais limpas e eficientes. Entretanto, é importante notar que a cláusula IF só pode lidar com uma única condição. Se você precisar lidar com várias condições, deve considerar o uso do CASE ou IF ELSE em blocos de procedimentos. Abaixo selecionamos algumas ótimas dicas de leitura pra quem quer se aprofundar no tema.
Código Expresso
SELECT nome, credito,
IF(credito > 500, 'Bom', 'Ruim') AS status_credito
FROM clientes;
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