From 08a70fe76ddda7500817fdb947559de39b0b850d Mon Sep 17 00:00:00 2001
From: utam0k <k0ma@utam0k.jp>
Date: Sun, 12 Sep 2021 00:58:35 +0900
Subject: [PATCH] reduce duplicate codes bacause of try_get()  to make it a
 little easier to read.

---
 src/database/mod.rs      |   7 +++
 src/database/mysql.rs    | 108 +++++++++++++++++----------------------
 src/database/postgres.rs |  26 +++++-----
 src/database/sqlite.rs   |  22 ++++----
 4 files changed, 81 insertions(+), 82 deletions(-)

diff --git a/src/database/mod.rs b/src/database/mod.rs
index 18014a1..beec60f 100644
--- a/src/database/mod.rs
+++ b/src/database/mod.rs
@@ -49,3 +49,10 @@ pub trait TableRow: std::marker::Send {
     fn fields(&self) -> Vec<String>;
     fn columns(&self) -> Vec<String>;
 }
+
+#[macro_export]
+macro_rules! get_or_null {
+    ($value:expr) => {
+        return Ok($value.map_or("NULL".to_string(), |v| v.to_string()));
+    };
+}
diff --git a/src/database/mysql.rs b/src/database/mysql.rs
index 16d7b6c..a9eaace 100644
--- a/src/database/mysql.rs
+++ b/src/database/mysql.rs
@@ -1,3 +1,5 @@
+use crate::get_or_null;
+
 use super::{Pool, TableRow, RECORDS_LIMIT_PER_PAGE};
 use async_trait::async_trait;
 use chrono::{NaiveDate, NaiveDateTime, NaiveTime};
@@ -7,6 +9,8 @@ use sqlx::mysql::{MySqlColumn, MySqlPoolOptions, MySqlRow};
 use sqlx::{Column as _, Row as _, TypeInfo as _};
 use std::time::Duration;
 
+const NULL: &str = "NULL";
+
 pub struct MySqlPool {
     pool: sqlx::mysql::MySqlPool,
 }
@@ -353,85 +357,69 @@ impl Pool for MySqlPool {
 
 fn convert_column_value_to_string(row: &MySqlRow, column: &MySqlColumn) -> anyhow::Result<String> {
     let column_name = column.name();
+
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<String> = value;
-        return Ok(value.unwrap_or_else(|| "NULL".to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        Ok(value.unwrap_or_else(|| NULL.to_string()))
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<&str> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<i8> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<i16> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<i32> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<i64> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<f32> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<f64> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<u8> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<u16> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<u32> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<u64> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<rust_decimal::Decimal> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<NaiveDate> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<NaiveTime> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<NaiveDateTime> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<chrono::DateTime<chrono::Utc>> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<serde_json::Value> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
-    }
-    if let Ok(value) = row.try_get(column_name) {
+        get_or_null!(value)
+    } else if let Ok(value) = row.try_get(column_name) {
         let value: Option<bool> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
+    } else {
+        anyhow::bail!(
+            "column type not implemented: `{}` {}",
+            column_name,
+            column.type_info().clone().name()
+        )
     }
-    Err(anyhow::anyhow!(
-        "column type not implemented: `{}` {}",
-        column_name,
-        column.type_info().clone().name()
-    ))
 }
diff --git a/src/database/postgres.rs b/src/database/postgres.rs
index f8219a8..c574d93 100644
--- a/src/database/postgres.rs
+++ b/src/database/postgres.rs
@@ -1,3 +1,5 @@
+use crate::get_or_null;
+
 use super::{Pool, TableRow, RECORDS_LIMIT_PER_PAGE};
 use async_trait::async_trait;
 use chrono::{NaiveDate, NaiveDateTime, NaiveTime};
@@ -467,19 +469,19 @@ fn convert_column_value_to_string(row: &PgRow, column: &PgColumn) -> anyhow::Res
     let column_name = column.name();
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<i16> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<i32> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<i64> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<rust_decimal::Decimal> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<&[u8]> = value;
@@ -495,7 +497,7 @@ fn convert_column_value_to_string(row: &PgRow, column: &PgColumn) -> anyhow::Res
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<NaiveDate> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: String = value;
@@ -503,31 +505,31 @@ fn convert_column_value_to_string(row: &PgRow, column: &PgColumn) -> anyhow::Res
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<chrono::DateTime<chrono::Utc>> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<chrono::DateTime<chrono::Local>> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<NaiveDateTime> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<NaiveDate> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<NaiveTime> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<serde_json::Value> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get::<Option<bool>, _>(column_name) {
         let value: Option<bool> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<Vec<String>> = value;
diff --git a/src/database/sqlite.rs b/src/database/sqlite.rs
index 6ca8e98..a8144cb 100644
--- a/src/database/sqlite.rs
+++ b/src/database/sqlite.rs
@@ -1,3 +1,5 @@
+use crate::get_or_null;
+
 use super::{Pool, TableRow, RECORDS_LIMIT_PER_PAGE};
 use async_trait::async_trait;
 use chrono::NaiveDateTime;
@@ -351,43 +353,43 @@ fn convert_column_value_to_string(
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<&str> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<i16> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<i32> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<i64> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<f32> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<f64> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<chrono::DateTime<chrono::Utc>> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<chrono::DateTime<chrono::Local>> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<NaiveDateTime> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     if let Ok(value) = row.try_get(column_name) {
         let value: Option<bool> = value;
-        return Ok(value.map_or("NULL".to_string(), |v| v.to_string()));
+        get_or_null!(value)
     }
     Err(anyhow::anyhow!(
         "column type not implemented: `{}` {}",