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fix code snippets
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@alex-dukhno
alex-dukhno committed May 18, 2021
1 parent 4cbfc93 commit e2fbd7d
Showing 1 changed file with 31 additions and 31 deletions.
62 changes: 31 additions & 31 deletions docs/RFCs/text/2021-05-15-Type-System.md
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Original file line number Diff line number Diff line change
Expand Up @@ -23,13 +23,13 @@ Possibly it impacts `extended query protocol` and future research for workloads
PostgreSQL converts implicitly string into number if one of the parameter is a number

```sql
postgres=# select 1 + '1';
select 1 + '1';
?column?
----------
2
(1 row)

postgres=# select '1' + 1;
select '1' + 1;
?column?
----------
2
Expand All @@ -39,7 +39,7 @@ postgres=# select '1' + 1;
However, fails when both of them are literals

```sql
postgres=# select '1' + '1';
select '1' + '1';
ERROR: 42725: operator is not unique: unknown + unknown
LINE 1: select '1' + '1';
^
Expand All @@ -51,12 +51,12 @@ HINT: Could not choose a best candidate operator. You might need to add explici
Implicit and explicit cast of string literals give same results:

```sql
postgres=# select 1 + 'abc';
select 1 + 'abc';
ERROR: 22P02: invalid input syntax for type integer: "abc"
LINE 1: select 1 + 'abc';
^

postgres=# select 1 + cast('abc' as int);
select 1 + cast('abc' as int);
ERROR: 22P02: invalid input syntax for type integer: "abc"
LINE 1: select 1 + cast('abc' as int);
```
Expand All @@ -66,13 +66,13 @@ LINE 1: select 1 + cast('abc' as int);
Date literals and numbers works with explicit cast. Implicit cast is not supported for date literals in any position.

```sql
postgres=# select 1 + cast('2021-01-01' as date);
select 1 + cast('2021-01-01' as date);
?column?
------------
2021-01-02
(1 row)

postgres=# select 1 + '2021-01-01';
select 1 + '2021-01-01';
ERROR: 22P02: invalid input syntax for type integer: "2021-01-01"
LINE 1: select 1 + '2021-01-01';
^
Expand All @@ -81,13 +81,13 @@ LINE 1: select 1 + '2021-01-01';
Subtraction works only if number is the second argument

```sql
postgres=# select 1 - cast('2021-01-01' as date);
select 1 - cast('2021-01-01' as date);
ERROR: 42883: operator does not exist: integer - date
LINE 1: select 1 - cast('2021-01-01' as date);
^
HINT: No operator matches the given name and argument types. You might need to add explicit type casts.

postgres=# select cast('2021-01-01' as date) - 1;
select cast('2021-01-01' as date) - 1;
?column?
------------
2020-12-31
Expand All @@ -102,7 +102,7 @@ Other arithmetic operations are not supported
Operations of timestamps and numbers are not supported with neither implicit nor explicit casts.

```sql
postgres=# select cast('2021-05-16 12:24:07' as timestamp) + 1;
select cast('2021-05-16 12:24:07' as timestamp) + 1;
ERROR: 42883: operator does not exist: timestamp without time zone + integer
LINE 1: select cast('2021-05-16 12:24:07' as timestamp) + 1;
^
Expand All @@ -114,7 +114,7 @@ HINT: No operator matches the given name and argument types. You might need to
Operations of time and numbers are not supported with neither implicit nor explicit casts.

```sql
postgres=# select cast('12:24:07' as time) + 1;
select cast('12:24:07' as time) + 1;
ERROR: 42883: operator does not exist: time without time zone + integer
LINE 1: select cast('12:24:07' as time) + 1;
^
Expand All @@ -126,13 +126,13 @@ HINT: No operator matches the given name and argument types. You might need to
PostgreSQL does not convert implicitly boolean to numbers, however, explicit cast helps

```sql
postgres=# select 1 + true;
select 1 + true;
ERROR: 42883: operator does not exist: integer + boolean
LINE 1: select 1 + true;
^
HINT: No operator matches the given name and argument types. You might need to add explicit type casts.

postgres=# select 1 + cast(true as int);
select 1 + cast(true as int);
?column?
----------
2
Expand All @@ -144,28 +144,28 @@ postgres=# select 1 + cast(true as int);
Numeric literal implicitly has `integer` type unless first parameter is in a `bigint` range.

```sql
postgres=# select 32767 + 2147483647;
select 32767 + 2147483647;
ERROR: 22003: integer out of range

postgres=# select 32767 + 32767;
select 32767 + 32767;
?column?
----------
65534
(1 row)

postgres=# select pg_typeof(32767 + 32767);
select pg_typeof(32767 + 32767);
pg_typeof
-----------
integer
(1 row)

postgres=# select 9223372036854775 + 2147483647;
select 9223372036854775 + 2147483647;
?column?
------------------
9223374184338422
(1 row)

postgres=# select pg_typeof(9223372036854775 + 2147483647);
select pg_typeof(9223372036854775 + 2147483647);
pg_typeof
-----------
bigint
Expand All @@ -175,7 +175,7 @@ bigint
Number literals with floating-point explicitly converted into `numeric` type

```sql
postgres=# select pg_typeof(123.123);
select pg_typeof(123.123);
pg_typeof
-----------
numeric
Expand All @@ -187,46 +187,46 @@ postgres=# select pg_typeof(123.123);
Supported only for integer types.

```sql
postgres=# select 1 & true;
select 1 & true;
ERROR: 42883: operator does not exist: integer & boolean
LINE 1: select 1 & true;
^
HINT: No operator matches the given name and argument types. You might need to add explicit type casts.
```

```sql
postgres=# select 1 & 'true';
select 1 & 'true';
ERROR: 22P02: invalid input syntax for type integer: "true"
LINE 1: select 1 & 'true';
^
```

```sql
postgres=# select 1 & 1.2;
select 1 & 1.2;
ERROR: 42883: operator does not exist: integer & numeric
LINE 1: select 1 & 1.2;
^
HINT: No operator matches the given name and argument types. You might need to add explicit type casts.
```

```sql
postgres=# select 1 & cast('2021-01-01' as date);
select 1 & cast('2021-01-01' as date);
ERROR: 42883: operator does not exist: integer & date
LINE 1: select 1 & cast('2021-01-01' as date);
^
HINT: No operator matches the given name and argument types. You might need to add explicit type casts.
```

```sql
postgres=# select 1 & '12:00:00'::time;
select 1 & '12:00:00'::time;
ERROR: 42883: operator does not exist: integer & time without time zone
LINE 1: select 1 & '12:00:00'::time;
^
HINT: No operator matches the given name and argument types. You might need to add explicit type casts.
```

```sql
postgres=# select 1 & '2021-01-01 12:00:00'::timestamp;
select 1 & '2021-01-01 12:00:00'::timestamp;
ERROR: 42883: operator does not exist: integer & timestamp without time zone
LINE 1: select 1 & '2021-01-01 12:00:00'::timestamp;
^
Expand All @@ -236,21 +236,21 @@ HINT: No operator matches the given name and argument types. You might need to
### Date, Time and Intervals

```sql
postgres=# select '2020-01-01'::date + '12:00:00'::time;
select '2020-01-01'::date + '12:00:00'::time;
?column?
---------------------
2020-01-01 12:00:00
(1 row)
```

```sql
postgres=# select '2020-01-01'::date + interval '1 day';
select '2020-01-01'::date + interval '1 day';
?column?
---------------------
2020-01-02 00:00:00
(1 row)

postgres=# select '2020-01-01'::date + interval '1 year';
select '2020-01-01'::date + interval '1 year';
?column?
---------------------
2021-01-01 00:00:00
Expand All @@ -262,20 +262,20 @@ postgres=# select '2020-01-01'::date + interval '1 year';
Limit supports integer and floating-point numbers

```sql
postgres=# select * from test limit 1;
select * from test limit 1;
i | i2 | i3
---+----+----
1 | 2 | 1
(1 row)

postgres=# select * from test limit 1.5;
select * from test limit 1.5;
i | i2 | i3
---+----+----
1 | 2 | 1
1 | 1 | 2
(2 rows)

postgres=# select * from test limit 1.49;
select * from test limit 1.49;
i | i2 | i3
---+----+----
1 | 2 | 1
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