Explain SQL Functions available in SQL

CHARACTER FUNCTIONS
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select concat('Good ',' Morning')"My Name" from dual
My Name
Good Morning
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select initcap('good')"My Name" from dual;
My Name
Good
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select lower('GoOd')"My Name" from dual;
My Name
good
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select upper('GoOd')"My Name" from dual;
My Name
GOOD
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select lpad('Good',10,'$')"My Name" from dual;
My Name
$$$$$$Good
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select rpad('Good',10,'$')"My Name" from dual;
My Name
Good$$$$$$
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select substr('GoodDay',4,2)"My Name" from dual;
My Name
dD
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select ltrim(' Good ')"My Name" from dual;
My Name
Good
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select rtrim(' Good ')"My Name" from dual;
My Name
Good
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select trim(' Good ')"My Name" from dual;
My Name
Good
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select INSTR('Good Morning','o',2,3)"My Name" from dual;
My Name
7
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select Length('Good Morning')"My Name" from dual;
My Name
12
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NUMERIC FUNCTIONS
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select mod(15,12)"My Value" from dual;
My Value
3
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select power(15,12)"My Value" from dual;
My Value
129746337890625
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select round(152.49,1)"My Value" from dual;
My Value
152.5
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select trunc(152.49,1)"My Value" from dual;
My Value
152.4
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select round(158.49,-1)"My Value" from dual;
My Value
160
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select trunc(158.49,-1)"My Value" from dual;
My Value
150
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select sign(-158.49)"My Value" from dual;
My Value
-1
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select sign(158.49)"My Value" from dual;
My Value
1
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select sqrt(256)"My Value" from dual;
My Value
16
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