klausa WHERE

Berlaku untuk:centang ditandai ya Databricks SQL centang ditandai ya Databricks Runtime

Membatasi hasil klausa FROM kueri atau kueri bertumpuk berdasarkan kondisi yang ditentukan.

Sintaks

WHERE boolean_expression

Parameter

  • boolean_expression

    Ekspresi apa pun yang dievaluasi menjadi jenis hasil BOOLEAN. Anda dapat menggabungkan dua atau beberapa ekspresi menggunakan operator logis seperti AND atau OR.

    Jika ekspresi berisi fungsi agregat, fungsi jendela, atau fungsi generator, Azure Databricks menaikkan INVALID_WHERE_CONDITION.

Kondisi kesalahan umum

Contoh

> CREATE TABLE person (id INT, name STRING, age INT);
> INSERT INTO person VALUES
    (100, 'John',   30),
    (200, 'Mary', NULL),
    (300, 'Mike',   80),
    (400, 'Dan' ,   50);

-- Comparison operator in `WHERE` clause.
> SELECT * FROM person WHERE id > 200 ORDER BY id;
 300 Mike 80
 400  Dan 50

-- Comparison and logical operators in `WHERE` clause.
> SELECT * FROM person WHERE id = 200 OR id = 300 ORDER BY id;
 200 Mary NULL
 300 Mike   80

-- IS NULL expression in `WHERE` clause.
> SELECT * FROM person WHERE id > 300 OR age IS NULL ORDER BY id;
 200 Mary null
 400  Dan   50

-- Function expression in `WHERE` clause.
> SELECT * FROM person WHERE length(name) > 3 ORDER BY id;
 100 John   30
 200 Mary NULL
 300 Mike   80

-- `BETWEEN` expression in `WHERE` clause.
SELECT * FROM person WHERE id BETWEEN 200 AND 300 ORDER BY id;
 200 Mary NULL
 300 Mike   80

-- Scalar Subquery in `WHERE` clause.
> SELECT * FROM person WHERE age > (SELECT avg(age) FROM person);
 300 Mike  80

-- Correlated Subquery in `WHERE` clause.
> SELECT * FROM person AS parent
   WHERE EXISTS (SELECT 1 FROM person AS child
                  WHERE parent.id = child.id
                    AND child.age IS NULL);
 200 Mary NULL

-- Aggregate functions are not allowed in `WHERE`.
> SELECT * FROM person WHERE max(age) > 10;
  Error: INVALID_WHERE_CONDITION
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