Flink SQL> SET ‘table.local-time-zone’ = ‘Europe/Berlin’;
— 返回 25201
Flink SQL> SELECT UNIX_TIMESTAMP(‘1970-01-01 08:00:01.001’, ‘yyyy-MM-dd HH:mm:ss.SSS’);
— 返回 1
Flink SQL> SELECT UNIX_TIMESTAMP(‘1970-01-01 08:00:01.001 +0800’, ‘yyyy-MM-dd HH:mm:ss.SSS X’);
— 返回 25201
Flink SQL> SELECT UNIX_TIMESTAMP(‘1970-01-01 08:00:01.001 +0800’, ‘yyyy-MM-dd HH:mm:ss.SSS’);
— 返回 -9223372036854775808
Flink SQL> SELECT UNIX_TIMESTAMP(‘1970-01-01 08:00:01.001’, ‘yyyy-MM-dd HH:mm:ss.SSS X’);

WHERE
  CURRENT_WATERMARK(ts) IS NULL
  OR ts > CURRENT_WATERMARK(ts)

— 返回 f0，f1中第一个非空的值，如果 f0 和 f1 都是 NULL，则返回 ‘default’ COALESCE(f0, f1, ‘default’) ```

— TRUE
‘1’ IS JSON
‘[]’ IS JSON
‘{}’ IS JSON
— TRUE
‘“abc”‘ IS JSON
— FALSE
‘abc’ IS JSON
NULL IS JSON
— TRUE
‘1’ IS JSON SCALAR
— FALSE
‘1’ IS JSON ARRAY
— FALSE
‘1’ IS JSON OBJECT
— FALSE
‘{}’ IS JSON SCALAR
— FALSE
‘{}’ IS JSON ARRAY
— TRUE
‘{}’ IS JSON OBJECT

— TRUE
SELECT JSON_EXISTS(‘{“a”: true}’, ‘$.a’);
— FALSE
SELECT JSON_EXISTS(‘{“a”: true}’, ‘$.b’);
— TRUE
SELECT JSON_EXISTS(‘{“a”: [{ “b”: 1 }]}’,
  ‘$.a[0].b’);
— TRUE
SELECT JSON_EXISTS(‘{“a”: true}’,
  ‘strict $.b’ TRUE ON ERROR);
— FALSE
SELECT JSON_EXISTS(‘{“a”: true}’,
  ‘strict $.b’ FALSE ON ERROR);

— NULL
JSON_STRING(CAST(NULL AS INT))
— ‘1’
JSON_STRING(1)
— ‘true’
JSON_STRING(TRUE)
— ‘“Hello, World!”‘
JSON_STRING(‘Hello, World!’)
— ‘[1,2]’
JSON_STRING(ARRAY[1, 2])

— “true”
JSON_VALUE(‘{“a”: true}’, ‘$.a’)
— TRUE
JSON_VALUE(‘{“a”: true}’, ‘$.a’ RETURNING BOOLEAN)
— “false”
JSON_VALUE(‘{“a”: true}’, ‘lax $.b’
    DEFAULT FALSE ON EMPTY)
— “false”
JSON_VALUE(‘{“a”: true}’, ‘strict $.b’
    DEFAULT FALSE ON ERROR)
— 0.998D
JSON_VALUE(‘{“a.b”: [0.998,0.996]}’,’$.[“a.b”][0]’
    RETURNING DOUBLE)
— “right”
JSON_VALUE(‘{“contains blank”: “right”}’, ‘strict $.[‘’contains blank’’]’ NULL ON EMPTY DEFAULT ‘wrong’ ON ERROR)

— ‘{ “b”: 1 }’
JSON_QUERY(‘{ “a”: { “b”: 1 } }’, ‘$.a’)
— ‘[1, 2]’
JSON_QUERY(‘[1, 2]’, ‘$’)
— NULL
JSON_QUERY(CAST(NULL AS STRING), ‘$’)
— ‘[“c1”,”c2”]’
JSON_QUERY(‘{“a”:[{“c”:”c1”},{“c”:”c2”}]}’,
    ‘lax $.a[].c’)
— 将结果包装到数组中
— ‘[{}]’
JSON_QUERY(‘{}’, ‘$’ WITH CONDITIONAL ARRAY WRAPPER)
— ‘[1, 2]’
JSON_QUERY(‘[1, 2]’, ‘$’ WITH CONDITIONAL ARRAY WRAPPER)
— ‘[[1, 2]]’
JSON_QUERY(‘[1, 2]’, ‘$’ WITH UNCONDITIONAL ARRAY WRAPPER)
— 必须包装标量才能返回
— NULL
JSON_QUERY(1, ‘$’)
— ‘[1]’
JSON_QUERY(1, ‘$’ WITH CONDITIONAL ARRAY WRAPPER)
— 路径表达式为空/存在错误时的行为
— ‘{}’
JSON_QUERY(‘{}’, ‘lax $.invalid’ EMPTY OBJECT ON EMPTY)
— ‘[]’
JSON_QUERY(‘{}’, ‘strict $.invalid’ EMPTY ARRAY ON ERROR)

— ‘{}’
JSON_OBJECT()
— ‘{“K1”:”V1”,”K2”:”V2”}’
JSON_OBJECT(‘K1’ VALUE ‘V1’, ‘K2’ VALUE ‘V2’)
— 表达式作为值
JSON_OBJECT(‘orderNo’ VALUE orders.orderId)
— ON NULL
JSON_OBJECT(KEY ‘K1’ VALUE CAST(NULL AS STRING) NULL ON NULL)   — ‘{“K1”:null}’
JSON_OBJECT(KEY ‘K1’ VALUE CAST(NULL AS STRING) ABSENT ON NULL) — ‘{}’
— ‘{“K1”:{“K2”:”V”}}’
JSON_OBJECT(
  KEY ‘K1’
  VALUE JSON_OBJECT(
    KEY ‘K2’
    VALUE ‘V’
  )
)

— ‘[]’
JSON_ARRAY()
— ‘[1,”2”]’
JSON_ARRAY(1, ‘2’)
— 表达式作为值
JSON_ARRAY(orders.orderId)
— ON NULL
JSON_ARRAY(CAST(NULL AS STRING) NULL ON NULL) — ‘[null]’
JSON_ARRAY(CAST(NULL AS STRING) ABSENT ON NULL) — ‘[]’
— ‘[[1]]’
JSON_ARRAY(JSON_ARRAY(1))

— ‘{“Apple”:2,”Banana”:17,”Orange”:0}’
SELECT
  JSON_OBJECTAGG(KEY product VALUE cnt)
FROM orders

— ‘[“Apple”,”Banana”,”Orange”]’
SELECT
  JSON_ARRAYAGG(product)
FROM orders