matchPrefixSuffix

matchPrefixSuffix(textCol, prefix, suffix, [scoreColName])

textCol 待查询的列，即 PKEY 存储引擎中设置了文本索引的列。

prefix STRING 类型标量，用于指定待查询的前缀。

suffix STRING 类型标量，用于指定待查询的后缀。

scoreColName 可选参数，STRING 类型标量，表示输出结果中文本匹配得分列的列名。默认值为空，此时不输出得分列。匹配得分代表数据在分区内的匹配程度，不同分区的分数不可比较。

该函数用于 SQL 语句的 WHERE 子句，针对 PKEY 存储引擎中设置文本索引的列进行前缀和后缀匹配，检查是否有词同时满足前缀和后缀条件，并返回匹配成功的行。

// 构造数据
stringColumn = ["There are some apples and oranges.","Mike likes apples.","Alice likes oranges.","Mike gives Alice an apple.","Alice gives Mike an orange.","John likes peaches, so he does not give them to anyone.","Mike, can you give me some apples?","Alice, can you give me some oranges?","Mike traded an orange for an apple with Alice."]
t = table([1,1,1,2,2,2,3,3,3] as id1, [1,2,3,1,2,3,1,2,3] as id2, stringColumn as remark) 
if(existsDatabase("dfs://textDB")) dropDatabase("dfs://textDB")
db = database(directory="dfs://textDB", partitionType=VALUE, partitionScheme=[1,2,3], engine="PKEY")
pt = createPartitionedTable(dbHandle=db, table=t, tableName="pt", partitionColumns="id1",primaryKey=`id1`id2,indexes={"remark":"textindex(parser=english, full=false, lowercase=true, stem=true)"})
pt.tableInsert(t)

// 匹配包含以 m 为前缀，ke 为后缀的单词的行
select * from pt where matchPrefixSuffix(remark,"m","ke")