overlay

overlay

overlay 介绍

overlay(input, replace, pos[, len]) - 从位置 pos 开始,用 replace 替换 input,替换的长度为 len。

Examples:

> SELECT overlay('Spark SQL' PLACING '_' FROM 6);
 Spark_SQL
> SELECT overlay('Spark SQL' PLACING 'CORE' FROM 7);
 Spark CORE
> SELECT overlay('Spark SQL' PLACING 'ANSI ' FROM 7 FOR 0);
 Spark ANSI SQL
> SELECT overlay('Spark SQL' PLACING 'tructured' FROM 2 FOR 4);
 Structured SQL
> SELECT overlay(encode('Spark SQL', 'utf-8') PLACING encode('_', 'utf-8') FROM 6);
 Spark_SQL
> SELECT overlay(encode('Spark SQL', 'utf-8') PLACING encode('CORE', 'utf-8') FROM 7);
 Spark CORE
> SELECT overlay(encode('Spark SQL', 'utf-8') PLACING encode('ANSI ', 'utf-8') FROM 7 FOR 0);
 Spark ANSI SQL
> SELECT overlay(encode('Spark SQL', 'utf-8') PLACING encode('tructured', 'utf-8') FROM 2 FOR 4);
 Structured SQL

Since: 3.0.0